Question 1173681
x hours at 80 km/h
7-x hours at 30 km/h
80x+30(7-x)=485
80x+210-30x=485
50x=275 km
x=5.5 hours at 80 km/h or 440 km
1.5 hours at at 30 km/h or 45 km

1.5 hours