Rakesh can do a piece of work in 45 days, and Manoj can do the same work in 90 days. Find the time required to complete the same work if they work on alternate days and Rakesh starts the work.
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 60 days
Given that
Rakesh can do a piece of work in 45 days
Manoj can do the same work in 90 days
Total work = LCM (45, 90) = 90
The efficiency of Rakesh = 90/45 = 2
The efficiency of Manoj = 90/90 = 1
if they work on alternate days and Rakesh starts the work
(2 + 1 = 3) work will be completed in 2 days
90 work will be completed in 2 × 30 = 60 days
Hence, the complete work will be finished in 60 days