Umesh and Ramesh can complete a work in 28 and 21 days, respectively. Starting with Umesh, they work on alternate days. In how many days will the work be completed?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is Option 4 i.e 24 days.
Umesh can complete a work = 28 days
Ramesh can complete a work = 21 days
Total work = LCM of 28 and 21 = 84 unit
Efficiency of Umesh = 84/28 = 3 unit per day and Ramesh = 84/21 = 4 unit per days
They work alternatively,
So, their 2 days work = 3 + 4 = 7 unit
2 days = 7 unit
2 days × 12 = 7 × 12 unit
24 days = 84 unit
So, the work will be completed in 24 days.