A can complete a piece of work in 4 hours and B can complete it in 6 hours. In how much time (in hours) will they together complete the work?

Explanation

​ Information Given: Time taken by A = 4 hours Time taken by B = 6 hours Concept/Formula Used: Work = LCM of individual times Efficiency = Work / Time Total Time = Total Work / Combined Efficiency Explanation: LCM of 4 and 6 = 12 Total work = 12 units Efficiency of A = 12 / 4 = 3 units/hour Efficiency of B = 12 / 6 = 2 units/hour Combined efficiency = 3 + 2 = 5 units/hour Time taken together = 12 / 5 = 2.4 hours = 2.4 hours = 2 hours + 0.4 hours = 0.4 × 60 = 24 minutes = 2 hours 24 minutes