Question

Bus A and Bus B leave the bus depot at 4 pm. Bus A takes 15 minutes to do its route and bus B takes 35 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

The bus will meet again at the depot at 5.45 pm

Explanation:

Find the prime factors of 15:

15 = 3 x 5

Find the prime factors of 35:

35 = 5 x 7

Find the LCM:

LCM = 3 x 5 x 7

LCM = 105 mins

Find the time that the bus will be at the depot together:

Time = 4pm + 105 mins

Time - 4 pm + 1 hour + 45 mins

Time = 5.45 pm