Question

Bus A and Bus B leave the bus depot at 9 am.

Bus A takes 30 minutes to complete its route once and bus B takes 40 minutes to complete its route once.
If both buses continue to repeat their route, at what time will they be back at the bus depot together?
Assume the buses have no breaks in between routes.
Give your answer as a 12-hour clock time.

Answer 1

11 a.m

Explanation:

The LCM of (30, 40) would be 120

So divide it by how many minutes in a hour to get 2 hours

so 2 plus 9 to get 11