1. A car travels along the route 10km, 5 km, 10km, 5 km in 30minutes. What is the average speed of the car?
2. A man of mass 50Kg ascends a flight of stairs 5m high in 5 seconds. If acceleration due to gravity is 10ms-1 , the power expended is?
#1) 30 minutes total, or 30 minutes for each leg? In any case, average speed is totaldistance/totaltime
#2) power = work/time = force*distance/time = 10*mass*distance/time
so plug in your numbers
(and g is in m/s^2, not m/s)