Elena bicycles 6 km/h faster than Dennis. In the same time it takes Dennis to bicycle 45 km, Elena can bicycle 63 km. How fast does each bicyclist travel?

Answer 1

X = rate of Dennis
X+6 = rate of Elena
time Dennis to travel 45 = time Elena travel 63.
distance = rate x time or
time = distance/rate
45/X = 63/(X+6)
Solve for X = Dennis' speed.
X+6 = Elena's speed.