Multiple choice general knowledge math & puzzles

One pipe can fill a tank three times as fast as another pipe. If together the two pipes can fill the tank in 36 minutes, then the slower pipe alone will be able to fill the tank in:

  1. 81 min

  2. 108 min

  3. 144 min

  4. 192 min

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Let the slower pipe's rate be x. The faster pipe's rate is 3x. Combined rate is 4x. In 36 minutes, they fill 4x * 36 = 144x units. The slower pipe alone takes (144x / x) = 144 minutes.