Question 913083

Gaining speed 60 -51= 9 mph
Time to catch up 4 hours
Head start 9*4=36 miles

Algebraic solution
9*4=36 miles head start
60*4-51*4=9*4
36 is less than 51 so he drove less than an hour

51t=36

t=36/51 0.71 hours or about 42.35 minutes