A can complete a work in 25 days and B can complete it in 30 days. If they work on it together for 5 days, then the fraction of the work that is left will be:

Explanation

Given: A can complete a work in 25 days and B can complete it in 30 days. Concept used: Total work = Efficiency of the work × time taken by the workers Calculation: LCM of 25 and 30 = 150 i.e total work Efficiency of A = 150/25 = 6 units/day Efficiency of B = 150/30 = 5 units/day Effective efficiency = 6 + 5 = 11 units/day Total work complete = 5 × 11 = 55 units Remaining 150 - 55 ⇒ 95 units Fraction of the work left = 95/150 ⇒ 19 30 ​ ∴ T he fraction of the work that is left will be