5 men can complete a piece of work in 16 days while 2 women can do it in 20 days. In how many days can 4 women and 2 men complete it?

Correct option is B

Given:

5 men can complete the work in 16 days

2 women can complete the same work in 20 days

Formula Used:

Total Work = Number of Workers × Days

Solution:

Total work for both of them is same, so

​$$5M\times 16 = 2W\times 20 \\ \ \\ \frac{M}{W}=\frac 12$$

Efficiency of Men = 1 and Efficiency of Women = 2

Now, 

​$$5 \times 1 \times 16 = (4\times 2+2\times 1)\times D \\ \ \\ 80 = 10 \times D \\ \ \\ \implies D = 8 \ days$$​​