Question

Two buses leave a station at the same time and travel in opposite directions. One bus travels 15 /kmh faster than the other. If the two buses are 366km apart after 2 hours, what is the rate of each bus? Note that the ALEKS graphing calculator can be used to make computations easier.

Answer 1

Since the buses travel in opposite directions, the speed at which they distance themselves is the sum of their speeds.
One bus travels at speed s.
The other bus travels at speed s + 15.
The sum of the speeds is s + s + 15 = 2s + 15

speed = distance/time

distance = speed * time

366 = (2s + 15) * 2

183 = 2s + 15

168 = 2s

s = 84

The slower bus travels at 84 km/h.

s + 15 = 84 + 15 = 99

The faster bus travels at 99 km/h.

Check:
In 2 hours, the slower bus travels 2 * 84 km = 168 km
In 2 hours, the faster bus travels 2 * 99 km = 198 km
In 2 hours, the buses are 198 km + 168 km = 366 km apart.
Our answer is correct.