Problema Solution
Lisa traveled to her cabin on the lake and back. The trip there took five hours and the trip back took six hours. She averaged 45 km/h on the return trip. Find the average speed of the trip there.
Answer provided by our tutors
let
v1 = the average speed of the trip to the lake
v2 = 45 km/h the average speed of the return trip
d = the distance in one direction
t1 = 5 hr the time of the trip to the lake
t2 = 6 hr the time of the return trip
since the average speed = distance/time we have
v1 = d/t1
v1 = d/5
v2 = d/t2
45 = d/6
d/6 = 45 multiply both sides by 6
d = 45*6
d = 270 km plug into v1 = d/5
v1 = 270/5
v1 = 54 km/h
the average speed of the trip there is 54 km/h.