Question

Use the subway train schedule below to answer the question.

Train Schedule
Train
Arrives Every...
Red line 8 minutes
Blue line
10 minutes
Yellow line 12 minutes
The red line and the blue line trains just arrived at the station. When will they next arrive at the station at
the same time?
They will next arrive at the station in
minutes.

Answer 1

40 minutes

Explanation:

The least common multiple of 8 minutes and 10 minutes is ...

LCM(8, 10) = 8·10/GCD(8, 10) = 80/2 = 40

The red and blue trains will arrive together again in 40 minutes.