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?

11 am

Step-by-step explanation:

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

Bus A takes 30 minutes to complete its route once

Bus B takes 40 minutes to complete its route once.

We solve this finding the Lowest Common Multiple of the minutes each bus uses to complete it's route

30 = 3 × 10

40 = 4 × 10

= 3 × 4 × 10

= 120 minutes

120 minutes after 9 am is

60 minutes = 1 hour

60 minutes = 1 hour

= 2 hours.

9am + 2 hours

= 11 am.

Therefore, they be back at the bus depot together at 11 am