Question

8 men and 2 children can do a work in 9 days.A child takes double the time to do a work than man. In how manydays 12 men can complete double the work?

Answer 1

2 child's = 1 men.
8 men + 2 childrens = 9 mens
then 9 mens do this work in 9 days.
then 1men do this workin 9x9 =81 days.
then 12 mens do this work in (81/12)=6.75days.
12 men complete double work in 2 x 6.5=13.5days.

Answer 2

a child takes double the time to do a work than man
that means , 1 man = 2 children
8 + 1 = 9 men can do a work in 9 days
1 men ... ... ... ... in 9 * 9 = 81 days
12 men ... ... ... ... in 81 / 12 days = 6.75 days
12 men can do Double work in 6.75 * 2 days = 13.5 days