Sharon and Ken drove to the service station - x hours.
They returned home - y hours.
60x - distance from home to the service station.
15y - distance from the service station to the home.
60x =15y ----> y = 4x
x+y = 4(hours)
x+y = 4
y=4x
x+4x=4
5x=4
x=4/5 h=0.8h
y=4x ----> y=4*(4/5)=16/5 =3.2h
60x=0.8*60=48 km
15y=15*3.2= 48 km
Answer: 48 km.