पाटीगणित (श्रीधराचार्य - प्राचीन संस्कृत टीका एवं प्रो. कृपाशंकर शुक्ल सविस्तार व्याख्या)
Patiganita of Sridharacharya with Commentary
श्रीधराचार्य (सम्पादक: प्रो. कृपाशंकर शुक्ल) द्वारा
MIXTURES, PURCHASE AND SALE 47
then another rate of purchase is x' articles per rûpa, where
x' = P₁/d + R( C₁x - P₁y )/d
= P₂/d + R( C₂x - P₂y )/d
...
= Pₙ/d + R( Cₙx - Pₙy )/d ,
where x = Ry - 1, y = C_λ + k, C_λ being the greatest of all C's and
k an arbitrary integer; the rate of sale being the same as before
( i.e., C_λ+k articles per rûpa ).
The rationale of this rule is as follows :
When D = 1 , the equations (1) of the previous rule may be
written as
RC₁x - P₁(Ry - 1) = RC₂x - P₂(Ry - 1) = ...
= RCₙx - Pₙ(Ry - 1) = M. (1)
Dividing throughout by d , and writing x' for x/d , P_r' for P_r/d,
and M' for M/d, we have
RC₁x' - P₁'(Ry - 1) = RC₂x' - P₂'(Ry - 1) = ....
= RCₙx' - Pₙ'(Ry - 1) = M'. (2)
The values of x , y satisfying (1) give one set of rates of purchase
and sale, and the values of x' , y satisfying (2) give another set of rates
of purchase and sale.
When M = Ry - 1 , a solution of (1) is, as before,
x = Ry - 1 ⎫
⎬ (3)
y = C_λ+k ⎭
and the corresponding solution of (2) is
x' = (Ry - 1)/d , i.e., M' ⎫
⎬ (4)
y = C_λ+k . ⎭
The rates of purchase and sale given by (3) are those already given
in Rule 60 ; those given by (4) are those mentioned in the present rule.
Since, from (2),
M' = P₁/d + R(C₁x - P₁y)/d = P₂/d + R(C₂x - P₂y)/d
= ... = Pₙ/d + R(Cₙx - Pₙy) ,
it is clear that the value of x' given by (4) is the same as that stated
in the above rule. It can be easily seen that M' is an integer.
Note. When D ≠ 1, then another rate of purchase will be D(Ry - 1)/d
articles per rûpa, where y = C_λ + k.
48 DETERMINATIONS
Ex. 76. The capitals of (three) men are 1, 3, and 5
(rûpas) or ⅓, ¼ and ½ (rûpas) (respectively). By purchasing and
selling (certain articles) at the same rates and by selling the
remnant articles at the rate of 1 for 3 (rûpas), they become
possessed of equal riches. (Find the rates of purchase and
sale).¹
Sub-rule for finding the rates of purchase and sale when each
of the remnant articles is sold for a fractional price :
62. When the remnant-price (i.e., the price at which
each remnant article is sold) is fractional (lit. has a denomi-
nator), reduce it along with the capitals to a common
denominator (and remove the denominators as before), and
multiply the rates of purchase and sale resulting from them
(by applying Rule 60) by the common denominator.²
That is, if the capitals of the n persons and the remnant-price
reduced to a common denominator, be as follows
Capitals : C₁/D , C₂/D , C₃/D , ... , Cₙ/D rûpas
Remnant-price : (R/D) rûpas,
then x = D² ( (R/D)y - 1 ) ,
and y = D (C_λ + k) ,
C_λ being the greatest of all C's and k an arbitrary integer.
The rationale of this rule is as follows :
As before, equating the wealths of the n persons after all the articles
have been sold away, we get [see equations (1) of Rule 60 (notes)]
(R/D) · C₁x - P₁D ( (R/D)y - 1 ) = (R/D) · C₂x - P₂D ( (R/D)y - 1 )
= ... = (R/D) · Cₙx - PₙD ( (R/D)y - 1 ) ,
¹ Cf. GSS, vi. 103½, 104½; GK, I, p. 96, lines 2-6, and p. 97, lines 7-9.
² Cf. GSS, vi. 107½. For another rule, see GSS, vi. 109½; GK, I, p. 98,
lines 2-7.
MIXTURES. PURCHASE AND SALE 49
or RC₁x - P₁D² ( R/D y - 1 ) = RC₂x - P₂D² ( R/D y - 1 )
= ... = RCₙx - PₙD² ( R/D y - 1 ) = N, say. (1)
Let x = N = D²( R/D y - 1 ), then
RCᵣ - Pᵣ = 1, (2)
for r = 1, 2, ..., n.
But ((Cᵣ/D)x) / y = Pᵣ + Aᵣ/y,
where Aᵣ is the remainder when Cᵣx/D is divided by y, so that, when
x = D²( R/D y - 1 ),
Pᵣ = Cᵣx / Dy - Aᵣ / y
= [ Cᵣ D² ( R/D y - 1 ) ] / Dy - Aᵣ / y
= RCᵣ - (Cᵣ D + Aᵣ) / y. (3)
Therefore we must have
y > CᵣD, for all r,
or y > C_λD,
where C_λ is the greatest of all C's.
Hence a solution of (1) is
x = D²( R/D y - 1 ),
y = D(C_λ + k),
k being an arbitrary integer.
Ex. 77. The capitals of four men are 1½, 2, 3, and 5
rûpas. By purchasing and selling (certain articles) at the same
rates, and by selling the remnant articles at the rate of 1 for ½
(of a rûpa), they become possessed of equal riches. (Find the
rates of purchase and sale).¹
¹ Cf. GSS, vi. 108½, 110½; GK, I, p. 99, lines 2-5 and 15-18.
50 DETERMINATIONS
Rule for finding out how a specified number of creatures of
given rates can be bought for a specified price :
63-64. By the price of one creature of any variety
multiply the rate-creatures (of other varieties) in the order in
which they have been stated (in the problem) (and also the
number of creatures to be bought). From the products (corres-
ponding to the rate-creatures) severally subtract the respec-
tive rate-prices of the creatures (and from the product
corresponding to the number of creatures to be bought sub-
tract the specified price). Now multiply the various remain-
ders, excepting that obtained by subtracting the specified
price, by optional numbers (multipliers) which are to be
chosen in such a way that (i) the resulting products when
added together may yield (the remainder obtained by sub-
tracting) the specified price as sum, and (ii) on taking the
products of those multipliers and the respective rate-prices,
a negative number or zero may not be obtained for the multi-
plier of the creature which is without a multiplier. (The multi-
pliers for the various creatures, obtained in this way, when
multiplied by the respective rate-creatures, will give the
number of creatures of the different varieties that will be
bought for the specified price ; and the same multipliers
when multiplied by the rate-prices of the respective creatures
will give the prices that will be paid for the creatures of the
respective varieties).¹
For the explanation of this rule see under Ex. 78-79.
Ex. 78-79. Pigeons are sold at the rate of 5 for 3 (rûpas),
cranes at the rate of 7 for 5 (rûpas), swans at the rate of 9 for
7 (rûpas), and peacocks at the rate of 3 for 9 (rûpas). Knowing
the rates as stated above, bring 100 birds for 100 rûpas
for the amusement of the prince.²
¹ Cf. GK, I, p. 92, vv. 34(ii)-35. For other rules see GSS, vi. 146½, 151.
² The same example occurs in GSS, vi. 152-153; BBi (ASS), p. 163,
vs. 138; GK, I, p. 93, lines 2-5. A similar problem occurs in BM, III, E 3,
58 verso, which may be stated as : ‘A man earns 3 maṇḍas in a day, a
woman 1½ maṇḍas in a day, and a sûḍha ½ maṇḍa in a day. If 20 of
them earn 20 maṇḍas in a day, how many of each category are there?’
MIXTURES. PURCHASE AND SALE 51
Let the number of pigeons, cranes, swans, and peacocks bought for
100 rûpas, and the prices paid for the respective birds be as follows :
Pigeons Cranes Swans Peacocks
Number 5x 7y 9z 3u } (1)
Price 3x 5y 7z 9u
Then we have
5x+7y+9z+3u = 100 , (2)
3x+5y+7z+9u = 100 . (3)
Multiplying (2) by 3 (which is the price of one peacock) and
subtracting (3) therefrom, we have
12x+16y+20z = 200 . (4)
This is an indeterminate equation having an indefinitely large
number of solutions. But we are in the present case concerned only with
those positive and non-zero solutions of (4), which make
5x , 7y , 9z , and 3u
positive integers.
Proceeding by trial, we obtain the following sixteen such solutions
of (4) :
(1) x=3, y=4, z=5 . (9) x=4, y=7, z=2 .
(2) x=11, y=3, z=1 . (10) x=8, y=4, z=2 .
(3) x=1, y=8, z=3 . (11) x=12, y=1, z=2 .
(4) x=6, y=3, z=4 . (12) x=5, y=5, z=3 .
(5) x=2, y=6, z=4 . (13) x=9, y=2, z=3 .
(6) x=4, y=2, z=6 . (14) x=7, y=1, z=5 .
(7) x=3, y=9, z=1 . (15) x=1, y=3, z=7 .
(8) x=7, y=6, z=1 . (16) x=2, y=1, z=8 .
The corresponding values of u are obtained from (2).
Substituting these values of x, y, z, and u in (1), we obtain sixteen
valid solutions of the problem. (For actual solutions, see the answer).
The above analysis explains the basis of the foregoing rule (Rule
63-64). It may be observed that the multipliers mentioned in the rule
refer to the variables x, y, z, and u.
Indological Truths
52 DETERMINATIONS
Ex. 80. (The rates of sale) of pomegranates, mangoes,
and wood-apples are respectively 1 for 2 (rûpas), 5 for 3 (rûpas),
and 2 fruits for 1 (rûpa). Bring 100 (fruits) for 80 (rûpas).¹
(v) MEETING OF TWO TRAVELLERS
Rule for finding the time in which the fast traveller, who starts
travelling on the same track after the slow traveller has
already covered a specified distance, would overtake the slow
traveller :
65. By the difference between the speeds per day of the
fast and slow travellers divide the distance already travelled
by the slow traveller. This gives the time (in days in which
the fast traveller would overtake the slow one).²
Ex. 81-82. When a person, travelling ( at the speed of )
8 yojanas per 5 minus ½ days, has already travelled for 6 minus
¼ days, another person, who travels ( at the speed of) 3 yojanas
a day, starts travelling (from the same place) along the same
track. Say, after calculating, when the latter traveller would
overtake the former.³
Rule for finding the time when two travellers, one fast and
the other slow, who, starting simultaneously from the
same place, are destined to go to a specified distance
and then to come back by the same track, will meet each other
on the way, one going ahead and the other coming back :
66(i). The (length of the) track divided by half the
sum of the speeds per day (of the two travellers) gives the
time (in days) at meeting.⁴
The time at meeting is evidently measured since the start of travel.
Ex. 83. One man travels ( at the speed of) 8 yojanas
(a day) and another (at the speed of) 2 yojanas (a day).
(They start simultaneously from the same place, and after
reaching the destination come back by the same track).
¹ Cf. GSS, vi. 147½-149, 150.
² Cf. BM, III, A 13, 3 recto; GSS, vi. 326½.
³ Cf. BM, III, B4, 4 recto; E 2, 53 recto; E 2, 53 verso; GSS, vi. 327½.
⁴ Cf. GSS, vi. 319 (ii).
MIXTURES. WAGES AND PAYMENTS 53
The (length of the) track is 100 yojanas. Say where is the
meeting (of the two), one going ahead and the other coming
back.¹
Sub-rule for finding the length of the track :
66(ii). The time of meeting multiplied by half the sum
of the speeds per day (of the two travellers) gives the length of
the track.
Sub-rule for finding the speed of one of the two travellers :
67(i). The (length of the) track as divided by the time
of meeting, being doubled and then diminished by the speed
(of one of the two travellers) gives the other speed (i.e., the
speed of the other traveller).
(vi) WAGES AND PAYMENTS
Rule for finding the wages for carrying a bottle of oil when
some oil falls down on the way due to a hole in the bottle :
67(ii). Give half the wages for the quantity fallen down
(on the way) and full for the rest.²
It can be easily seen that the wages prescribed in this rule corres-
pond to the average load carried by the porter.
Ex. 84-85. While a leathern oil-bottle (kutapa), filled
with 200 palas of oil, was being carried (by a porter) to a
distance of 8 yojanas for 5 paṇas (as wages), a hole hap-
pened to occur in the bottom of it through which the oil
leaked out (on the way) continuously. If 20 palas of oil be left
(in the bottle), what wages should be paid (to the porter)?³
Rule for finding the amounts to be paid to a dancing party
by the spectators, who see the dance for different parts of the
day, the amount to be paid to the dancing party for the whole
day being given:
68. The succeeding parts of the day, each diminished
by the preceding one, should be multiplied by the ‘fruit’
¹ Cf. BM, III, 9 verso ; GSS, vi. 321-321½
² Cf. GK, I, p. 102, lines 6-7.
³ Read bhṛte for dhṛte in the text. For a similar example, see GK, I,
p. 103, lines 2-5.
54 DETERMINATIONS
(phala); then having divided them severally by the respec-
tive numbers of spectators, add the preceding results to
the succeeding ones. The results thus obtained being multi-
plied by the numbers of spectators who go away (at the end
of the respective parts of the day), give the amounts to be paid
(to the dancing party by the spectators who go away at the
end of the respective parts of the day).¹
By the word ‘fruit’ (phala) is meant here the amount to be paid to
the dancing party for the whole day.
The above rule is based on the assumption that the spectators
have to pay the dancing party in proportion to the time of seeing the
dance. That is, if the spectators who see the dance for the whole day
pay 96 rūpas in all, then the spectators who see the dance for ¼ of a day
will have to pay 96/4, i.e., 24 rūpas in all.
For the illustration of the rule see under the next example.
Ex. 86-87. One man saw a dance for one quarter of the
day, another for two quarters of the day, another for
three quarters of the day, and (yet) another till the end of the
day. The dancing party has to be paid by them a sum of
ninety six rūpas in all. If payment is to be made in propor-
tion to the time of seeing the dance, how much of that (sum)
should be paid by each of them separately?
Solution. Writing down the parts of the day during which the
various spectators saw the dance, we have
1/4 2/4 3/4 4/4
Diminishing the succeeding part by the preceding one, we get
1/4 1/4 1/4 1/4
Multiplying each of these by the fruit (i.e., by 96), we get
24 24 24 24
Dividing these numbers by the number of spectators who saw the
dance during the respective parts of the day, we get
6 8 12 24
¹ See GSS, vi. 230.
MIXTURES. THE CISTERN PROBLEM 55
Adding the preceding numbers to the succeeding ones, we get
6 14 26 50
Multiplying by the number of spectators who go away at the end of
the respective parts of the day, we get
6 14 26 50
Hence the spectator who saw the dance for ¼ of the day will have
to pay 6 rûpas ; the spectator who saw the dance for ²⁄₄ of the day will have
to pay 14 rûpas ; the spectator who saw the dance for ¾ of the day will
have to pay 26 rûpas ; and the spectator who saw the dance for the whole
day who will have to pay 50 rûpas.
Ex. 88. A palanquin is to be carried to a distance of
3 krośas by 10 men for 100 (rûpas as wages). Of those (men),
2, 3, and 5 stop away after going over 1, 2, and 3 krośas respec-
tively. (Calculate the wages of each of them separately).¹
Ex. 89-90. Five Brâhmaṇas, enchanters of stotras
(“hymns in praise of gods”), were invited by a certain person
to take part in the worship of the five faces of the five-faced
god Śiva on (a remuneration of) 300 rûpas. And they, on the
completion of worship of one, two, three, four, and five faces
respectively, went away (from the place of worship) one by
one.² Say what are their remunerations (separately).
(vii) THE CISTERN PROBLEM
Rule for finding the time in which a cistern would be filled
up by a number of drains flowing into it simultaneously, when
the times in which the cistern is filled up by each drain
separately are given :
69. Having divided unity severally by the (given)
fractions (of time), take the sum of the quotients and by that
sum divide unity (again) : this will give the time in which
the cistern is filled up (when all the drains are simultaneously
opened to flow into it).³
¹ Cf. GSS, vi. 231-232.
² What is meant is this : when the worship of the first face was com-
pleted by all the five Brâhmaṇas, one Brâhmaṇa left the place of worship ;
when the worship of the second face was completed by the remaining four
Brâhmaṇas, one more Brâhmaṇa left the place of worship ; when the
worship of the third face was completed by the remaining three Brâhmaṇas,
one more Brâhmaṇa left the place of worship ; and so on.
³ Cf. MSi, xv. 43; L (ASS), p. 91, vs. 96 ; GK, I, p. 94, line 2-3.
56 DETERMINATIONS
That is, if n drains severally fill up a cistern in
a₁/b₁, a₂/b₂, ... , aₙ/bₙ of a day,
then all the drains working together will fill up the cistern in
1 / (b₁/a₁ + b₂/a₂ + ... + bₙ/aₙ) of a day.
Ex. 91. In what time will the (four) drains, which
severally fill up a cistern in ½, ¼, ⅕, and ⅙ of a day, fill up
that cistern if they are opened simultaneously (to flow into
it) ? 1
(viii) WAGES PAID FROM THE COMMODITY
Rule for finding the wages of a porter who carries a commo-
dity over a part of the stipulated distance, when the wages
are to be paid out of the commodity itself :
70. (To obtain the wages for a part of the stipulated
distance) divide half the product of the commodity and the
stipulated distance as diminished by the square root extracted
from the square of half the product of the commodity and the
stipulated distance as diminished by the (continued) product
of the distance (already) gone over, the distance to be gone
over, the commodity, and the stipulated wages, by the
distance which is still to be gone over.²
Assuming that the (stipulated) wages for carrying a articles over the
(stipulated) distance d are w articles (out of those a articles), let the
wages for carrying those a articles over a distance d₁, where d₁ < d, be
x articles (out of those a articles). Then calculating at the same rate, the
wages for carrying the remaining a - x articles over the remaining distance
d - d₁ are equal to
(a - x) (d - d₁)x / (ad₁) articles.
But the remaining wages being w - x articles, we have
(a - x) (d - d₁)x / (ad₁) = w - x ,
1 Similar examples occur in Pṛthûdaka Svâmî's (860 A.D.) comm.
on BrSpSi, xii. 9; L (ASS), p. 91, vs. 97 ; GK, I, p. 94, lines 5-6.
- Cf. GSS, vi. 226. For another rule, see GK, I, p. 103, lines 10-15.
- MIXTURES. WAGES PAID FROM COMMODITY 57
or, (d - d₁) x² - adx + awd₁ = 0 ,
whence x = [ad/2 ± √((ad/2)² - awd₁ (d - d₁))] / (d - d₁) .
Taking the negative sign before the radical, we have the rule stated
above. The positive sign is rejected because it makes x > w.
Ex. 92. If for carrying 24 jack-fruits over a distance of
5 krośas (a porter) is to get 9 of those jack-fruits, what will
he get if he carries them over a distance of 2 krośas (only) ?¹
Rule for finding the distances over which two porters carry
a commodity in turn, when the wages paid to the porters
out of the commodity carried by them are given :
- The first and the second loads (i.e., the loads carried
by the first and the second porters), each multiplied by
the wages for the other, being added together, the resul-
ting sum is (to be taken as) the divisor (of the following
results) : the results obtained by multiplying the products
of the wages received (for each of the loads) and the
(total) distance (gone over by the porters), each by the other
load. This gives the distances (gone over by the first and the
second porters separately).²
Suppose that the first porter carries a articles over a distance x
(unknown) and gets b articles out of those a articles as wages, and that
the second porter carries the remaining a - b articles over the remaining
distance d - x and gets c articles as wages. Then, we have
c = b(a - b)(d - x) / ax ,
whence x / ((a - b)b) = (d - x) / ac = d / (ac + (a - b)b)
Hence the above rule.
Ex. 93-94. Twenty-four jack-fruits were carried (over
a certain distance) by one (person) for 4 out of those (24) jack-
fruits as wages ; the remaining jack-fruits were carried (over
the remaining distance) by another person for 5 of them (as
wages). The load was thus carried by the two (person) over
¹ Cf. GSS, vi. 227. Also see GK, I, p. 103, lines 17-20.
² See GSS, vi. 228.
58 DETERMINATIONS
a distance of 5 krośas (in all). Say, O learned, how much of
that distance was gone over by each of them ?¹
(ix) COMBINATIONS OF SAVOURS
Rule for finding the number of combinations that can be
formed out of a given number of savours (or things) by
taking 1, 2, 3, ...., all at a time :
72. Writing down the numbers beginning with 1 and
increasing by 1 up to the (given) number of savours in the
inverse order, divide them by the numbers beginning with 1
and increasing by 1 in the regular order, and then multiply
successively by the preceding (quotient) the succeeding one.
(This will give the number of combinations of the savours
taken 1, 2, 3, ... , all at a time respectively).²
Let the given number of savours be six. Then the numbers
1, 2, 3,..., 6 are written down in the inverse order thus :
6 5 4 3 2 1
These are divided by the numbers 1, 2, 3, ... 6 respectively, so that
we get
6/1, 5/2, 4/3, 3/4, 2/5, 1/6.
Now multiplication is made successively by the preceding quotient of the
succeeding one. Thus we get
6/1, 6/1 × 5/2, 6/1 × 5/2 × 4/3, 6/1 × 5/2 × 4/3 × 3/4, 6/1 × 5/2 × 4/3 × 3/4 × 2/5,
6/1 × 5/2 × 4/3 × 3/4 × 2/5 × 1/6.
These, according to the rule, are respectively the numbers of combinations
of the six savours taken 1, 2, 3,..., 6 at a time.
Ex. 95. Friend, a cook prepares varieties of food with
the six savours, pungent, bitter, astringent, acid, saline, and
sweet. Say what is the (possible) number of varieties ?³
¹ A similar problem occurs in GSS, vi. 229.
² Cf. GSS, vi. 218 ; MSi, xv. 45(ii)-46 ; L (ASS), p. 106, vv. 112-113
(i); GK, II, pp. 318-319, vs. 58.
³ The same example occurs in GSS, vi. 219 ; GK, II, p. 319, Ex. 22.
MIXTURES. SPECIAL PROBLEMS 59
Rule for writing down the combinations of 2 or more savours
in a serial order :
73. To get the 2-savour combinations add the pre-
ceding savour to all the succeeding one’s in order ; and to get
the combinations of 3 or more savours add the preceding
savour to the (succeeding) combinations of 2 or more savours
which do not contain the preceding savour.
Let the six savours be denoted by
a b c d e f .
Then the 2-savour combinations are :
ab, ac, ad, ae, af ; bc, bd, be, bf ;
cd, ce, cf ; de, df ; ef.
The 3-savour combinations are :
abc, abd, abe, abf, acd, ace, acf, ade, adf, aef ;
bcd, bce, bcf, bde, bdf, bef ; cde, cdf, cef ; def.
The 4-savour combinations are :
abcd, abce, abcf, abde, abdf, abef, acde, acdf ;
acef, adef ; bcde, bcdf, bcef, bdef, cdef.
The 5-savour combinations are :
abcde, abcdf, abcef, abdef, acdef, bcdef.
The 6-savour combination is :
abcdef.
(x) CERTAIN SPECIAL TYPES OF PROBLEMS
Rule for solving problems on pillars (stambhoddeśaka¹) or
problems involving remainders (śeṣoddeśaka) :
74(i). To solve problems on pillars or problems involv-
ing remainders, divide the visible quantity (dṛśya) by one minus
(the sum of) the fractional parts (of the whole).²
¹ Mahāvīra calls stambha-jāti by the name bhāga-jāti, and Śrīpati
by the name dṛśya-jāti. See GSS, iv. 4(i) and GT, p. 41, vs. 55.
² Cf. GSS, iv. 4(i); GT, p. 41, vs. 55. Also see GK,I, p. 17, lines 14-19.
Mahāvīra gives a separate rule for the śeṣa-jāti. See GSS, iv. 4(ii). The
same rule is given by Āryabhaṭa II and Śrīpati. See MSi, xv. 20; GT,
p. 44, line 11.
50 DETERMINATIONS
Ex. 96. One-fourth, one-third, and one-sixth of a pillar
are respectively buried under the water, mud, and sand of a
river, and three cubits (of the pillar) are visible. Give out
the measure (of the length) of that (pillar).¹
Here the given fractions (of the pillar) are ¼, ⅓, and ⅙ ; and the
visible quantity (i.e., the visible part of the pillar) is equal to ‘ 3 cubits.’
Hence the length of the pillar
3
= ————————————————— , i.e., 12 cubits.
1 - (¼ + ⅓ + ⅙)
Ex. 97. After giving away one-half of a quantity, then
⅔ of what remains, then ¾ of what remains thereafter, and
then ⅘ of what remains thereafter, the residue left is 3.
(What is that quantity ?)²
Here the fractions (of the whole quantity) given away are
½, ⅔ of (1 - ½), ¾ of (1 - ½) (1 - ⅔) , and
⅘ of (1 - ½) (1 - ⅔) (1 - ¾) ,
i.e., ½, ⅓, ⅛, and ¹/₃₀ ;
and the visible quantity (i.e., the residue left) is 3 .
Hence the required quantity
3
= ——————————————————————— , i.e., 360 .
1 - (½ + ⅓ + ⅛ + ¹/₃₀)
Rule for solving problems involving differences (viśeṣoddeśaka):
74(ii). On subtracting the smaller quantity from the
greater quantity what remains is called the difference
(viśeṣa).³ (This having been done) the procedure (to be adop-
ted is the same as the other one (i.e., the previous one).⁴
Ex. 98. Of a herd of cows, one-half went away towards
the east and one-fourth towards the west, the difference of the
¹ Cf. GSS, iv. 5; GT, p. 41, vs. 56. For other examples see GSS, iv.
6-22 ;GT, p. 42, vs. 57 ; L (ASS), pp 47-48, vs. 53; GK, I, p. 20, lines 4-7,
10-13, 16-19.
² For other examples, see GSS, iv. 29-30, 31, 32; GT, p. 44, lines
20-23 ; p. 45, lines 16-19; L (ASS), pp. 49-51, vs. 54.
³ Mahāvīra does not differentiate between bhāga-jāti and viśeṣa-jāti
(or viśleṣa-jāti)). So he sets problems on the latter under the bhāga-jāti.
See GSS, iv. Ex. 23-27.
⁴ Cf. GT, p. 46, lines 10-13.
MIXTURES. SPECIAL PROBLEMS 61
two as multiplied by 2 and divided by 5 went away
towards the north, and three (cows) are left. (What is the
numerical strength of the herd ?)¹
Here the fractions (of the herd of cows) that went away in the
various directions are
½, ¼, and ⅖(½ - ¼)
i.e., ½, ¼, and ⅒ ;
and the visible quantity (i e., the number of cows left) is 3. Hence the
numerical strength of the herd
= 3 / [1 - (½ + ¼ + ⅒)] , i.e., 20 cows.
Rule for solving problems involving remainders due to sub-
traction of square root, etc. (mūlādiśeṣoddeśaka) : ²
75. When the visible quantity stands near a square
root, multiply the visible quantity by 4, then increase that by
the square of the pada (i.e., the co-efficient of the square root
of the unknown), then extract the square-root of that and
increase that by the pada, and then take the square of half of
that ; (and when the visible quantity stands near a fraction)
divide the visible quantity by one minus the fraction.³
The first part of this rule relates to the solution of the quadratic
equation of the type
x - p√x = d,
where p is the pada, d the visible quantity (dṛśya), and √x the positive
square root of x. The solution is correctly stated as
x = [ {√(4d + p²) + p} / 2 ]²
¹ For similar examples see GSS, iv. 23-27; GT, p. 46, lines 20-25;
L (ASS), p. 53, vs. 55.
² Mahāvīra and Śrīpati have called mūlādiśeṣa-jāti by the name
śeṣamūla-jāti.
³ Cf. GSS, iv. 40; GT, p. 48, lines 24-25.
62 DETERMINATIONS
The second part of the rule relates to the solution of the simple
equation of the type
x − (a/b) x = d′,
where a/b is the fraction and d′ the visible quantity. The solution is
correctly stated as
x = d′ / (1 − a/b).
Ex. 99. A number is diminished by its square root,
what remains is diminished by its one-sixth, what remains
after that is diminished by its square root, what remains after
that is diminished by its one-fifth, and what remains after
that is diminished by twice the square root of itself; the
residue now left is 8. (Find the number).¹
This problem reduces to the solution of the following equation :
x − √x − ⅙ (x − √x) − √[x − √x − ⅙ (x − √x)] − ⅕ {x − √x − ⅙ (x − √x)
− √[x − √x − ⅙ (x − √x)]} − 2 [x − √x − ⅙ (x − √x) − √[x − √x − ⅙ (x − √x)]
− ⅕ {x − √x − ⅙ (x − √x) − √[x − √x − ⅙ (x − √x)]}]^½ = 8,
which can be written as
x − √x = y, (1)
where y − ⅙ y = z, (2)
z − √z = u, (3)
u − ⅕ u = v, (4)
v − 2 √v = 8. (5)
Solving these equations in the inverse order, we get x = 36.
Hindu Method of Solution. Writing down the square roots and frac-
tions, which have been successively subtracted from the original number,
in order and then the visible quantity, we get
Square root, 1/6 part of the remainder, square root of the remainder, 1/5 part of the
remainder, 2 times the square root of the remainder, visible quantity 8.
──────────────────────────────────────────────────────────
¹ For other examples see, GSS, iv. 41, 42-45, 46; GT, p. 49, lines
7-10; p. 50, lines 2-5.
MIXTURES. SPECIAL PROBLEMS 63
Since the visible quantity stands near a square root, therefore per-
forming the operations prescribed in the first part of the rule, we get
[ (√(4 × 8 + 2²) + 2) / 2 ]², i.e., 16.
This is the number which when diminished by 2 times the square root
of itself yields 8 as remainder.
Now treat this (16) as the visible quantity. Since it stands near a
fraction, therefore performing the operation prescribed in the second part
of the rule, we get
16 / (1 - 1/5), i.e., 20.
This is the number which when diminished by 1/5 of itself yields 16
as remainder.
Now treat this (20) as the visible quantity. Since it stands near a
square root, therefore performing the operations prescribed in the first
part of the rule, we get
[ (√(4 × 20 + 1) + 1) / 2 ]², i.e., 25.
This is the number which when diminished by its square root yields 20 as
remainder.
Now treat this (25) as the visible quantity. Since this stands near a
fraction, therefore performing the operation prescribed in the second part
of the rule, we get
25 / (1 - ⅙), i.e., 30.
This is the number which when diminished by its ⅙ yields 25 as
remainder.
Now treat this (30) as the visible quantity. Since this stands near a
square root, therefore performing the operations prescribed in the first
part of the rule, we get
[ (√(4 × 30 + 1) + 1) / 2 ]², i.e., 36.
This is the number which being diminished by its square root yields 30
as remainder.
Since all quantities in the statement of the problem are now
exhausted, no further operation is needed. The required number is thus
obtained to be 36.
64 DETERMINATIONS
Rule for solving problems in which the visible quantity is the
remainder due to the subtraction of a fraction of the unknown
and also a multiple of the square root of the unknown
(bhâgamûlâgroddeśa) :¹
76. After having divided the pada (i.e., the co-efficient
of the square root of the unknown) and the visible quantity
(or ultimate remainder, agra) by one minus the fraction, add
the square of half the first quotient to the second quotient,
then take the square root of that, then increase that by half
the first quotient, and then multiply that by itself.²
This rule is meant to solve problems reducing to a quadratic
equation of the type
x - (a/b)x - p√x = d ,
where a/b is the 'fraction', p the 'pada', d the visible quantity, and √x
the positive square root of x.
The solution is correctly stated as
x = [ p / {2(1 - a/b)} + √{ (p / {2(1 - a/b)})² + d / (1 - a/b) } ]²
Ex. 100. One-third of a troop of monkeys together
with one-third of itself has gone to the tank ; the square root
(of the whole troop) is afflicted with thirst ; and the remain-
ing two monkeys are sitting under the mango tree. (What is
the number of monkeys in the troop ?)³
Rule for solving problems involving two visible quantities,
the square root of the original number, and remainders due
to subtraction of fractional multiples of remainders (ubhayâgra-
mûlaśeṣoddeśa):⁴
77. Take the continued product of units severally
diminished, as before, by the fractional multiples of remain-
――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――
¹ Mahâvîra calls bhâgamûlâgra-jâti by the name mûla-jâti, Śrîpati by
the name mûlâgra-bhâga-jâti, and Nârâyaṇa by the name ṛṇâṁśavimûla-jâti.
² Cf. GSS, iv. 33; GT, p. 50 lines 27-28 (contd. on p. 51, lines 1-2).
Also see GK, I, p. 21, lines 2-6.
³ For other examples see GSS, iv. 34, 35, 36, 37, 38, 39; GT, p. 51,
lines, 11-14; p. 52, lines 16-19; p. 53, lines 17-20; GK, I, p. 23, lines 15-16,
18-19, and p. 24, lines 1-2.
⁴ Mahâvîra calls ubhayâgramûlaśeṣa-jâti by the name dviragraśeṣamûla-
jâti, and Śrîpati by the name ubhayâgradṛśya-jâti.
MIXTURES. SPECIAL PROBLEMS 65
ders as the divisors of the pada as well as the (last) visible
quantity ; to the second quotient also add the first visible
quantity. After that apply the previous rule (starting with
‘add the square of half the first quotient’).¹
This rule applies to problems which reduce to the solution of the
quadratic equation of the type
(1 - a/b) (1 - c/d) (1 - e/f) (x - d₁) - p√x = d₂ ,
where a/b, c/d, e/f are the fractional multiples of remainders, p is the pada,
d₁, d₂ the first and last visible quantities, and √x denotes the positive
square root of x, as before.
According to the above rule, this equation should be first trans-
formed into the form
x - {p / [(1 - a/b)(1 - c/d)(1 - e/f)]} √x = {d₂ / [(1 - a/b)(1 - c/d)(1 - e/f)]} + d₁ ,
and then solved by the previous rule.
Ex. 101. After giving away one (out of a certain
number), then one-sixth of what remains, then one-fourth of
what remains after that, then one-third of what remains after
that, and then the square root of the original number, the
residue left is 5. (What is that number ?)²
Rule of inversion :
78. (Proceeding from the visible quantity backwards,
make) addition subtraction, subtraction addition, multi-
plication division, division multiplication, square square-
root, and square-root square : this is stated to be the method
of inversion.³
Ex. 102. Say what (is that number which) being multi-
plied by 5/2, then divided by 3, then squared, then increased
by 9, then reduced to its square root, and then diminished by
1, becomes 4.⁴
¹ Cf. GSS, iv. 47 ;GT, p. 54, lines 21-24.
² For other examples see GSS, iv. 48, 49, 50; GT, p. 55, lines 7-10;
p. 56, lines 8-11 ; p. 5 , lines 19-22.
³ Cf. Ā, ii. 28; BrSpSi, xviii. 14(17); GSS, vi. 286; MSi, xv. 23;
GT, p. 65, vs. 83; SiŚe, xiii. 13; L (ASS), p. 42, vs. 48; GK, I, p. 46,
lines 13-16.
⁴ For similar examples see GSS, vi 287; GT, p. 66, vs. 84; p. 67,
vs. 85; L (ASS), p. 43, vs. 50.
66 DETERMINATIONS
(2) Determinations pertaining to series (śreḍhî-vyavahâra)
(i) SERIES IN ARITHMETIC PROGRESSION
(GEOMETRICAL INTERPRETATION)
Form of a series-figure (śreḍhî-kṣetra) :
79. As in the case of an earthen drinking glass
(śarâva) the width at the base is smaller and at the top
greater, so also is the case with a series-figure (śreḍhî-kṣetra).
The altitude (lambaka) of that (series-figure) is equal
to the number of terms (gaccha) of the (corresponding)
series.
The series-figure contemplated here is a plane figure resembling a
trapezium with equal flank sides
If a series be
a+(a+d)+(a+2d)+... to n terms,
then, according to the second part of the verse, the altitude of the corres-
ponding series-figure = n units, say n cubits.
80(i). The (partial) areas (phala) of the series-figure
for the successive cubits (kara) of the altitude form a series
which begins with the given âdi ('first term of the series')
and increases successively by the given caya ('common diffe-
rence of the series').
That is, the area of the series-figure for the first cubit of the altitude
= a, i.e., the first term of the series; the area of the series-figure for the
second cubit of the altitude = a+d, i.e., the second term of the series; the
area of the series-figure for the third cubit of the altitude = a+2d; and
so on.
Construction of a series-figure :
80(ii). I shall now describe the method for finding
the lengths of the base (i.e., lower side, bhû) and the face
(i.e., upper side, mukha) of the series-figure (corresponding
to the first term of the series).
81. The number of terms (pada), i.e., one, is the alti-
tude of the (corresponding) series-figure ; the first term of
Indological Truths