On a construction site, Pankaj and Tarun are two workers who have been assigned to break the stones for flooring. Pankaj can complete the work alone in 16 h, while Tarun will take 24 h. They decided to work on alternate hours so that they could take a rest in between. Pankaj starts in the first hour and then Tarun and so on. How many hours will they complete the work together if they work on the basis of alternate hours?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. 19.
Total work = LCM of 16 and 24 = 48
Efficiency of Pankaj = 48/16 = 3
Efficiency of Tarun = 48/24 = 2
Work done in 2 days = 3 + 2 = 5
Work done in 18 days = 5 × 9 = 45
Remaining work = 48 - 45 = 3
On the 19th day, work done by Pankaj = 3
Total time required = 18 + 1 = 19 days