Question

Ravi can complete a task in 6 days and Mohan can complete the task in 9 days. In how many days can Ravi and Mohan together complete the same task?
1. \(3\frac{3}{5}\) days
2. 9 days
3. 15 days
4. \(3\frac{2}{5}\) days

Answer 1

Correct Answer - Option 1 : \(3\frac{3}{5}\) days

Given:

Ravi can complete the task in 6 days

Mohan can complete the task in 9 days

Formula used:

Total work = Efficiency × Time

Calculation:

Taking L.C.M of 6 and 9

⇒ L.C.M of 6 and 9 = 18

⇒ Efficiency of Ravi = (18/6) = 3

⇒ Efficiency of Mohan = (18/9) = 2

Time taken by Ravi and Mohan together to complete the work = 18/(3 + 2) = 18/5

⇒ 18/5 = \(3\frac{3}{5}\;days\)

∴ Ravi and Mohan together can complete the task in \(3\frac{3}{5}\;days\).