Question

A bicyclist travels at a constant speed of 18 miles per hour. How long does it take the bicyclist to travel 90 miles?

Answer 1

He'll take 90/18 = 5 hours

Answer 2

Speed = Distance / Time

Therefore

Time = Distance / Speed.
So,
Time taken = 90 miles / 18 miles per hour.

Therefore
Time taken = 5 hours.