Question

The downtown bus leaves the station leaves the bus station every 15 min. The upstown bus leaves the station every 35 min. Both buses start the day leaving the station at 7:00 A.M. When is the next time both buses will leave the station at the same time?

Answer 1

The answer to this question is the next common multiple of 15 and 35.So the next common multiple is 5*3*7 = 105 min
Since the start time is 7 AM, the bus that leaves every 15 minutes will leave at 7 Am + 105 min = 8:45 AM
The bus that leaves every 35 min will leave at the same time 8:45.So the next time when these 2 buses will leave the station at the same time is 8:45 AM