Qudurat GAT Practice
ArithmeticQuestion 308 of 550

A pipe fills a tank in 6 hours. A drain empties the full tank in 12 hours. Both are opened together and the tank starts empty. After how many hours is the tank full?

  1. 4 hours
  2. 9 hours
  3. 12 hours
  4. 18 hours
Show answer

Correct answer: 12 hours

In one hour the tank gains 1/6 − 1/12 = 1/12 of its volume. So it fills in 12 hours.

Test structure: ETEC guide to the GAT

Practice arithmetic

Questions last reviewed: 21 October 2026