A contractor undertook to finish a certain work in 124 days and employed 120 men. After 64 days, he found that he had already done 2/3 of the work. How many men can be discharge now, so that the work finish in time?

Given, M₁ = 120, M₂ = 120 - n, D₁ = 64, D₂ = 60
W₁= 2/3 and W₂ = 1/3
According to the formula,
(M₁D₁) / W₁ = (M₂D₂) / W₂
⇒ [120 x (64/2)] / 3 = [(120 - n) x 60] / (1/3)
⇒ (120 x 64) / (2 x 60) = (120 - n)
⇒ (120 - n) = 64
∴ n = 120 - 64 = 56
Now, 56 men can be discharged to finish the work in time.