Two pipes A and B can fill a take in 20 and 30 minutes respectively. If both the pipes are used together, than how long will it take to fill the tank ?

Two pipes A and B can fill a take in 20 and 30 minutes respectively. If both the pipes are used together, than how long will it take to fill the tank ?

A 10

B 11

C 12

D 15

Solution

Correct Answer: Option C

Solution:

\(\frac{{20 \times 30}}{{20 + 30}} = \frac{{20 \times 30}}{{50}}\) = 12 min