Question

a train to new york city leaves every 7 minutes. Another train to Boston leaves the station every 6 minutes. Suppose it is 6:30 am right now. At what time will both trains leave the station together again if both of them left the station together at 6:30 am?

Answer 1

please the way is 13 minutes

Answer 2

Answer:

7.12 am

Step-by-step explanation:

If a train to new york city leaves every 7 minutes and another train to Boston leaves the station every 6 minutes

Then, the two trains leave together after a period equal to the LCM of their individual intervals.

LCM(7,6)=42

Therefore if started together, they leave at the same time again after every 42 minutes.

If both trains left the station at 6.30 am, they leave together again 42 mins later, which will be at  7.12 am