Answer to Question #141372 in Combinatorics | Number Theory for jeremiah

Question

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

Answer 1

Find the least common multplule of 15 and 25

$$15=3\cdot 5, 25=5\cdot 5$$

$$lcm=3\cdot5\cdot5=75$$

They both will be at the same stop again 75 minutes later.