20 men can finish a piece of work in 30 days working 6 hours per day. In how many days a group of 15 men will finish the work when they are working 8 hours per day?

30 50 20 10

30

Formula : M1 × D1 × H1 = M2 × D2 × H2 ⇒ 20 × 30 × 6 = 15 × D2 × 8 ⇒ D2 = \(\frac{20 × 30 × 6}{15 × 8}\) ⇒ D2 = 30 Days