Question

Bus A and Bus B leave the bus depot at 6 am.

Bus A takes 20 minutes to complete its route once and bus B takes 35 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

therefore = 8: 20 a.m

Explanation:

The time will they back at the bus depot together is shown below:

The factors of 20 minutes and 35 minutes are 5, 4 and 5, 7

So here the LCM is 5

Now

= 5 × 4 × 7

= 140 mins later

As the bus took off at 6 am

So,

Hours Mins

6 0

+ 2 20 (140 mins = 2 hrs 20 mins)

= 8 20

therefore = 8: 20 a.m