Every morning, an elderly man exercise by walking a certain distance at 4kph, rests for 20 minutes and rides back on his chauffeur-driver limousine at an average of 60 kph. If the total time of the trip is an hour and 8 minutes, how far does the man walk?

Question

anonymous · Answer

For distance s, we have 2s = 4t_1 +60t_2 and
                                   4/5 = t_1 + t_2

Solve simultaneously for s in terms of t_1 and substitute in s=4t_1.