Problema Solution
Dave travels 2/3 of the journey at a average speed of 12 mph. He then travels the remaining 30 miles of his journey in 3 hours. How long does his trip take
Answer provided by our tutors
let
d = the total distance of the trip
t = the total time of the trip
v1 = 12 mph the speed of the first (2/3)d miles
the rest of the trip is (1-(2/3))d = (1/3)d equal to 30 miles that is:
(1/3)d = 30 multiply both sides by 3
d = 90 mi
the time of the first part of the trip is:
d/v1 = 90/12 = 7.5 hr
the first 7.5 hours and the 3 hours make the total time of the trip:
7.5 + 3 = 10 hours.