Question
Quantitative Aptitude Question on Time Speed and Distance
Two pipes A and B would fill a cistern in 30 and 40 minutes respectively. Both pipes are opened. Determine the time the first pipe can be turned off so that the cistern may be just filled in 20 minutes?
A
After 10 minutes
B
After 15 minutes
C
After 20 minutes
D
After 22 minutes
E
After 25 minutes
Answer
After 15 minutes
Explanation
Solution
The correct option is (B): After 15 minutes