Answer: When the train on one route stop there every 9 minutes and trains on the other route stop there every 6 minutes, the time when they will stop at same time is 18 minutes.
Explanation:
From the information, the train on one route stop there every 9 minutes and trains on the other route stop there every 6 minutes.
Therefore, the time when will they stop at same time will be the lowest common multiple for 9 and 6. This is 18. Therefore, 18 minutes is the appropriate answer.
Therefore, the the time when they will stop at same time is 18 minutes.