A alone can do a work in 20 days. B is 25% more efficient than A. A and B started working and worked for 4 days. If C alone completed the remaining job in 22 days. How many days C alone takes to complete the entire job?

Explanation

GIVEN: A alone can do work in 20 days. B is 25% more efficient than A. A and B started working and worked for 4 days. If C alone completed the remaining job in 22 days. CALCULATION: ⇒ B can do a work in 16 days. Let the total unit of work (LCM of 20 and 16) = 80 units. ⇒ A's one day work = 4 units. ⇒ B's one day work = 5 units. As A and B left after working for 4 days ⇒ Work done by A and B in 4 days = 36 units. ⇒ Work left = 44 units, which is done by C in 22 days. ⇒ C's one day work = 2 units. ∴ 80 units of work can be completed by C alone in 80/2 = 40 days.