Pipe A fills water 3 times as fast as pipe B. When the tank is empty and both pipes are opened together, the tank is full in 12 minutes. How long would pipe B alone take to fill the empty tank?
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → 48 minutes
If B fills 1 unit per minute, A fills 3 units per minute. The capacity is then the joint rate multiplied by the joint time.
Together: \(3+1=4\) units per minute
Capacity \(=4\times12=48\) units
B alone \(\displaystyle =\frac{48}{1}=48\) minutes