Question

A northbound bus and a southbound bus are at a bus stop at the same time. The northbound bus returns to the bus stop every 20 minutes and the southbound bus returns to the bus stop every 25 minutes. How long will it be before both busses are at the bus stop at the same time again?

Answer 1

5 stops for the north 4 stops for the south

Answer 2

Answer: It will be after 100 minutes both buses stop at the same time again.

Explanation:

Since we have given that

Number of minutes after which the northbound bus stops = 20 minutes

Number of minutes after which the southbound bus stops = 25 minutes

We need to find the number of minutes it will before both buses are at the bus stop at the same time again.

So, L.C.M. of 20 and 25 = 100

Hence, it will be after 100 minutes both buses stop at the same time again.