Given:
a.) Two buses leave a station at the same time and travel in opposite directions.
Let,
Speed of Bus A = s
Speed of Bus B = s + 15
b.) The two buses are 543 kilometers apart after 3 hours.
d = 543 km
t = 3 hrs.
We get,
Therefore,
the speed of the slower bus = 83 km/h
the speed of the faster bus = 83 km/h + 15 km/h = 98 km/h