Question

A man cycles from A to B a distance of 21 km in 1hr 40min.The road from A is level for 13 km and then it is uphill to B. The man's average speed on levels is 15km/hr.Find his average uphill speed.

Answer 1

time taken for man to travel along the level (t) = 13/15 in hours
time taken for man to travel along the uphill region = 100 mins - 60t = 48 mins or .8 hrs
distance of uphill 21 - 13 = 8 km
hence speed is 8/0.8 = 10 kmph