Total distance John drove=450 miles total time=8 hours let the number of hours he drove on highway be x, number of hours he drove on turnpike will be (8-x) hours since distance=speed*time distance traveled in highway=50x distance traveled in turnpike=60(8-x) thus the total distance will be: 50x+60(8-x)=450 simplifying the above 50x+480-60x=450 -10x=450-480 -10x=-30 thus x=3 hours Thus he drove on highway for 3 hours.
