Given, 4 men can complete a work in = 15 days 5 women can complete the same work in = 12 days 3 boys can complete the same work in = 20 days Formula: Total work = Efficiency × Time taken Calculation: Total work = 60 Efficiency of 4 men = 4 units/day ⇒ Efficiency of 1 man =
4
4
= 1 units/day Efficiency of 5 women = 5 units/day ⇒ Efficiency of 1 woman =
5
5
= 1 unit/day Efficiency of 3 boys = 3 units/day ⇒ Efficiency of 1 boys =
3
3
= 1 unit/day Time taken by 1 man, 1 woman and 1 boy together to complete the work ⇒