15 men can complete a piece of work in 5 days, while 20

Solution

One day work of a man = 1/(15 ×5) = 1/75 So, 3 days work of 8 men = 1/75 ×8 ×3 = 8/25 Remaining work = 1 - 8/25 = 17/25 One day work of a woman = 1/(20 ×5) = 1/100 According to the question Remaining work should be completed in 4 days Let the total number of women required to complete the remaining work in 4 days = x 4 days work of x women = 1/100 ×4 ×x = 17/25 x=17 Alternate Method: 15M ` ` 5 = 20W ` ` 5 M:W = 20:15 = 4:3 So 15M ` ` 5 = 8M ` ` 3 + xW ` ` 4 15 x 4 x 5 = 8 x 4 x 3 + x ` ` 3` ` 4 300 = 96 +12x 204 = 12x x=17