A bus leaves a station every 18 minutes and a train every 24 minutes. Both leave at 08:00. At what time do they next leave together?
Answer and explanation
Correct answer: D. 09:12
- Step 1: Find the lowest common multiple of 18 and 24: 72. Step 2. 72 minutes after 08:00 is 09:12. Answer: 09:12. Why not the others: 08:36: This is a bus time, 2 × 18 minutes, but the train does not leave then. 09:00: This is 60 minutes after 08:00, which is not a multiple of 18 minutes. 10:24: This is a common multiple, but not the first one.
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