If 4 men or 8 women can do a work in 12 days, then in how many days can 9 men and 6 women do the same work?

Correct option is B

Given:

4 men or 8 women can finish a work in 12 days.

Formula Used:

Work done = Number of workers $$\times$$​ Efficiency of each worker $$\times$$​ Time

Solution:

Let the efficiency of a man and a boy be M and W respectively.

According to the question,

4M =8W

M =2W

​$$(9 \times M +6 \times W) \times D = 8 \times W \times 12$$​        [Total Work]

​$$( 9 \times 2W + 6 \times W ) \times D = 96W$$​​

​$$24W \times D = 96W$$​​

​$$D= 4days$$​