math
posted by micah on .
please explain the steps:
Jim Williamson began a 96mile 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 6 hours.If Jim walks at a rate of 4 miles per hour and rides at 20 miles per hour, find the amount of time he spent on the bicycle.

time on bike = t hrs
time walking = 9t hrs
distance on bike = 20t miles
distance walking = 4(9t) mile
20t + 4(9t) = 96
solve for t