Shubhradeep
12 women can complete a project in 36 days and 15 men can complete the same project in 27 days. 16 women start working and after 6 days, they were replaced by x men. If x men complete the remaining work in 5 days then what is the value of x?
A. 40
B. 42
C. 45
D. 57
E. 63
12 women can complete a project in 36 days
So, 12 women in 6 days complete 6/36 = 1/6 th of the work
So, 1 woman in 6 days complete 1/(6*12) th of the work
So, 16 women in 6 days complete 16/(6*12) = 2/9 th of the work
Remaining work = 7/9 th part
We know that 15 men do the work in 27 days
So, to do the work in 1 day, we would need 15 * 27 men
So, to do the work in 5 days, we would need 15 * 27/5 = 81 men
So, to do 7/9 th of the work in 5 days, we would need 81 * 7/9 = 63 men
Thus, x = 63
Alt: Work of 12 women in 36 days = work of 15 men in 27 days
If efficiency of a woman = 1 unit of work per day, we have:
Total work = 12 * 36 units = 432 units
Also Work of 15 men in 27 days = 12 * 36 units
=> Efficiency of a man = 12*36/(15*27) = 16/15 unit per day
Work done by 16 women in 6 days = 16*6 = 96 units
Work remaining = 432 - 96 = 336 = Work done by x men in 5 days
=> 336 = x * 16/15 * 5
=> x = 63