Question

The Line A bus arrives at the bus stop every 25 minutes, and the line B bus arrives every 15 minutes. Both are at the bus stop right now. In how many minutes will both be at the bus stop again?

Answer 1

75 minutes

Explanation:

To respond to the problem posed, it is necessary to make use of the mathematical concept of Multiple Minimal Common, because the bus on line A arrives at the station in integer multiples of 25, while the bus on line B arrives at the station in multiples integers of 15. Therefore, the next time the two buses will coincide at the station must be at the same time a multiple of 15 and 25.

Multiples of 15: 15, 30, 45, 60, 75, 90, 105, 120, ...

Multiples of 25: 25, 50, 75, 100, 125, 150, ...

MCM (15, 25) = 75 minutes

Answer 2

75

Explanation:

The least common multiple of 25 = 5² and 15 = 3·5 is the least number that contains all of these factors: 3·5² = 75.

The buses will again meet at the bus stop in 75 minutes.