Jim began a 281​-mile bicycle trip to build up stamina for a triathlete competition.​ Unfortunately, his bicycle chain​ broke, so he finished the trip walking. The whole trip took 7 hours. If Jim walks at a rate of 3 miles per hour and rides at 43 miles per​ hour, find the amount of time he spent on the bicycle.

1 answer

time = distance/speed, so if he rode x miles on the bike,

x/43 + (281-x)/3 = 7

solve for x, and then x/43 is the time on the bike.