**Concept:** **The question tests on the area of Rates(Time and Work)**

**Solution:**

12 men take 36 days

12 men in 1 day do 1/36th of the work

1 man in 1 day does 1/12∗36

8 men in 1 day does 8∗1/12∗36=1/54

18 women take 60 days

18 women in 1 day do 1/60 th of the work

1 woman in 1 day does 1/18∗60

20 women in 1 day does 20∗1/18∗60=1/54

8 men and 20 women in 1 day does 1/54+1/54=1/27th of the work

Work done in 20 days = 20∗1/27=20/27 th work

The remaining work = 1 – 20/27=7/27

Using the concept of MAN DAYS = M1∗T1/W1=M2∗T2/W2

M1 = 1, T1 = 1, W1 = Work done by 1 woman in 1 day1/18∗60

M2 = x, T1 = 4, W2 = Work done by x woman in 4 days to finish7/27th of the work

1∗1/(1/18∗60)=x∗4/(7/27)

x=70

Option A