Question

maria bicycles 8 km/h faster than carlos. in the same time it takes carlos to bicycle 48 km maria can bicycle 72 km. how fast does each bicyclist travel?

Answer 1

carlos' rate ---x
maria's rate --- x+8

time for Carlo to ride 48 km = 48/x hrs
time for Maria to ride 72 km = 72/(x+8)
but their times are equal , so ...

solve 48/x = 72/(x+8)

Answer 2

Distance Speed time
Maria 72 x+8 t
Carlos 48 x t

t=72/x+8
t=48/x
72/x+8=48/x
cross multiply
72x=48(x+8)
72x=48x+384
subtract 48x from both side
24x=384
multiply both side by 24
x=16
x+8
16+8=24
Carlos travels 16 km/h
Maria travels 24 km/h