Problema Solution
Meg rowed her boat upstream a distance of 36 mi and then rowed back to the starting point. the total time of the trip was 20 hours. If the rate of the current was 8mph, find the average speed of the boat.
Answer provided by our tutors
let 'x' represent the average speed of the boat, then 'x-8' is the speed of the boat against the current and 'x+8' is the speed of the boat with the current
the overall average speed will factor out the speed of the current:
(x-8 + x+8)/2 = 2x/2 = x
distance = speed * rate
rate = distance / speed
overall average speed: (2*36)/20 = 3.6
the average speed of the boat was 3.6 mph