Question

Bus A and Bus B leave the bus depot at 3 pm.
Bus A takes 25 minutes to do its route and bus B takes 30 minutes to complete its route.
At what time are they both back at the bus depot together?
Give your answer as a 12-hour clock time.

Answer 1

Given:

(i) Bus A and Bus B leave the bus depot at 3 pm.

(ii) Bus A takes 25 minutes to do its route and bus B takes 30 minutes to complete its route.

To find:

(i) At what time are they both back at the bus depot together?

Solution:

The exact time in minutes of their meeting together at the depot can easily be calculated by taking the LCM of their route times (that is 25 and 30)

25 = 5*5

30 = 2*3*5

LCM = 2*3*5*5 = 150

So, after 150 minutes, they will meet again at the depot.

1 hour = 60 minutes.

So, 150 minutes = 2 hours 30 minutes.

They will meet again 2 hours 30 minutes from 3PM, and that is 5:30PM

So, they will meet again at 5:30PM