Rakib can complete a task in 30 minutes, and together with his brother Momin, he can complete the task in 20 minutes. How long would it take for Momin working along to complete the task ?

Rakib can complete a task in 30 minutes, and together with his brother Momin, he can complete the task in 20 minutes. How long would it take for Momin working along to complete the task ?

A 30

B 40

C 50

D 60

Solution

Correct Answer: Option D

Solution:

\(\frac{{30 \times 20}}{{30 - 20}} = \frac{{30 \times 20}}{{10}}\) = 60 min