Question

12 Men or 15 women can do a piece of work in
21 days. Find the number of days required to
complete the same work by 6 men and
10 women.​

Answer 1

12 men take 21 days to complete a piece of work. 1 man takes (12 × 21) = 252 days.

15 women take 21 days to complete a piece of work. 1 woman takes (15 × 21) = 315 days.

In 1 day, 1 man does (1/252) of the work.

In 1 day, 1 woman does (1/315) of the work.

In 1 day, 6 men and 10 women can do 6(1/252) + 10(1/315) = (1/18) of the work.

(1/18) of the work done in 1 day.

18(1/18) of the work done in 18 days.