Multiple choice

In a water management project, there is a large tank which is full of water. There are three pipes, Pipe A can fill the tank in 16 minutes, Pipe B can fill it in 24 minutes, and Pipe C can empty the tank in 8 minutes. If all three pipes are opened simultaneously, how long will it take to remove 1 3 of the tank's full capacity?

  1. 12 minutes

  2. 16 minutes

  3. 32 minutes

  4. 48 minutes

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

The net rate is 1/16 + 1/24 - 1/8 = -1/48 of the tank per minute. The tank therefore loses 1/48 of its capacity each minute. Removing 1/3 of the tank takes (1/3) × 48 = 16 minutes.

AI explanation

Pipe A fills at a rate of 1/16 per minute, pipe B fills at 1/24 per minute, and pipe C empties at 1/8 per minute. Using the net work formula, their combined rate is 1/16 + 1/24 - 1/8, which equals -1/48 of the tank per minute. Because the result is negative, the net action is emptying the tank at a rate of 1/48 per minute. To remove 1/3 of the tank's capacity, we divide 1/3 by 1/48, which results in 16 minutes.