Problema Solution
Alberto made a trip to his friend's house and back. The trip there took three hours and the trip back took four hours. He averaged 9.8 mph faster on the trip there than on the return trip. Find Alberto's average speed on the outbound trip.
Answer provided by our tutors
let
v = the speed on the return trip
v + 9.8 = the speed on the trip there
t1 = 3 hr the time of the trip there
t2 = 4 hr the time of the return trip
since speed = distance/time => distance = speed*time
v*t2 = (v + 9.8)*t1
4v = (v + 9.8)*3
by solving we find
v = 29.4 mph
click here to see the step by step solution of the equation
the speed of the outbound trip is 29.4 + 9.8 = 39.2 mph.