3 men can do a piece of work in 6 days. 5 women can do the same work in 18 days. If 4 men and 10 women work together, then how long will it take to finish the work?

(3 x 6) men = (5 x 18) women
18 men = 90 women
∴ 1 man = 5 women
∴ 4 men + 10 women
= 4 x 5 + 10 = 30 women
Given, M₁ = 5, M₂ = 20, D₁ = 18 ,
W₁ = W₂ = 1 and D₂ = ?
According to the formula, M₁D₁W₂ = M₂D₂W₁
⇒ 5 x 18 x 1 = 30 x D₂ x 1
∴ D₂ = 5 x 18/30 = 3 days