One shuttle leaves a terminal every 12 minutes and another leaves every 18 minutes. If both leave together at 8:00, after how many minutes will they next leave together?

Correct answer to question 20 (Arithmetic Reasoning): 36 minutes

Method

The shuttles coincide at a common multiple of their intervals, and the first one is the least common multiple. The multiples of 12 are 12, 24, 36, and 36 is the first that 18 also divides, so they leave together again after 36 minutes.