4 men and 6 woman get ? 1600 by doing a piece of work in 5 days. 3 men and 7 women get ? 1740 by doing the same work in 6 days. In how many days, 7 men and 6 women can complete the same work getting ? 3760?

Work for 1 st 2 days = (1/8) + (1/12) = 5/24
? Work for 8 days = (5/24) x (8/2) = 5/6
? Remaining work = 1- (5/6) = (6 - 5) / 6 = 1/6
On 9th day, A's work = 1/8

Remaining work after 9 days = (1/6) - (1/8) = (4 - 3) / 24 = 1/24
B will finish this work in (12 x 1)/24 = 1/2 day
Clearly, A worked for 5 days from starting.

? Work done by A in 5 days = (1/8) x 5 = 5/8
? A's share = (5/8) x 1280 = 5 x 160 = ? 800

Let man be represented by m and woman be represented by w.
? 2m + 1w = 1/14
? 14 x (2m + 1w ) = 1 ...(i)

and 4w + 2m = 1/8
8 x (4w + 2m) = 1 ...(ii)

On equating Eqs. (i) and (ii), we get
14 (2m + 1w) = 8 (4w + 2m)
? 28m + 14w = 32w + 16m
? 28m - 16m = 32w - 14w
? 12m = 18w
? m/w = 18/12 = 3/2
So, efficiency of 1 man and 1 woman is 3 : 2.
So, their wages must be in the same ratio
90/x = 3/2
[here, x = wages of a woman ]
? x = 90 x 2 / 3 = ? 60

Let the numbers of men, women and
children are 3k, 2k and k, respectively.
Given, 3k = 90
? k = 30
Number of women = 60
and number of children = 30

Let the men's, women's and children's
wages be ? 5p, ? 3p and ? 2p, respectively.
According to the question,
Total daily wages = ? 10350
? 90 x 5p + 60 x 3p + 30 x 2p = 10350
? p x (450 + 180 + 60) = 10350
? p = 10350/690 = 15
? Daily wages of a man = 15 x 5 = ? 75

Let the wages of 1 man, 1 woman and 1 boy are ? P, ? Q and ? R, respectively. According to the question,
3P + 2Q + 4R = 26 ....(i)
3P = 4Q ....(ii)
and 2Q = 3R ....(iii)

From Eqs. (i) and (ii), we get
4Q + 2Q + 4R = 26
? 6Q + 4R = 26.........................(iv)

From Eqs. (iii) and (iv), we get
9R + 4R = 26
? 13R = 26
? R = 2
From Eqs. (ii) and (iii), we get
Q = 3 and P = 4

? Wages of 4 men, 3 women and 2 boys
= (4 x 4) + (3 x 3) + (2 x 2)
= 16 + 9 + 4 = ? 29

Amount received by ( A + B + C) per day
= 5400/36 = ? 150
? A + B + C = ? 150.................(i)
Similarly, amount received by (A + C) per day
= 1880/20 = ? 94
? A + C = ? 94 ........................(ii)
Amount received by (B + C) per day
= 3040/40 = ? 76
? B + C = ? 76 ........................(iii)
From Eqs. (i) and (iii), we get
A + 76 = ? 150
A = 150 - 76 = ? 74
By putting the value of A in Eq. (ii), we get
74 + C = ? 94
? C = 94 - 74 = ? 20
Hence, amount received by C per day
= ? 20