Question

Two different buses start their routes at the same corner at 9 A.M. Buses from one route stop at the library every 9 minutes. Buses from the other route stop at the library every 12 minutes. In what number of minutes will both buses end up at the library?

Answer 1

Answer: In 36 minutes both buses will end up at the library.

Explanation:

Given: Buses from one route stop at the library every 9 minutes.

Buses from the other route stop at the library every 12 minutes.

The number of minutes in which both buses will end up at the library= LCM(9,12)

Now , 9= 3 x 3

12= 2 x 2 x 3

LCM(9,12) = 2 x 2 x 3 x 3 = 36

In 36 minutes both buses will end up at the library.