Tap A can fill a tank in 4 minutes while tap B can fill the same tank in 3 minutes. If both taps are opened at the same time, how long will it take them to fill the tank?

Answer 1

Let t = the time it takes for both taps to fill the tank together

t/4 + t/3 = 1

Multiply both sides by 12.

3t + 4t = 12

7t = 12

t = 12/7 = 1.7 minutes