City Hoppa run two buses starting from the same bus stop. One has a route of 25 minutes. & the other has a route of 55 minutes.Both buses leave the bus stop at 6.00am and run continously.
What is the next time that the buses will at the same stop together?



Answer :

You have to find the least common multiple (lcm) of 25 and 55.

To find lcm you have to seperate 25 and 55 to prime factors:
25= 5 * 5
55= 5 * 11
Both numbers has one same prime factor which is 5 (bolded). 
LCM is a multiplication of unique prime factors and one from each pair of the same prime factors, see it below:
[tex]lcm_{25,55}=5*5*11=275[/tex]

This means that the buses are going to meet at the same stop after 275 minutes from their start.
275 minutes are 4 hours and 35 minutes.
Buses start at 6.00 am, add 4 hours and 35 minutes to receive the time of their meeting which is 10.35 am.