Problema Solution
Bailey drives a truck for Express King Delivery and must make a special trip to a construction site that is 150 miles away. Bailey takes his time on the drive to the site, and his average speed is only 50 miles per hour. What must Bailey's average speed be on the drive back to Express King Delivery so that the average speed for his complete driving trip is 60 miles per hour?
Answer provided by our tutors
let
v1 = 50 mph the speed to he site
v2 = the speed from the site
v = 60 mph the average speed
d = 150 mi the distance of the trip in one direction
the average speed of the complete driving = the total distance/the total time
the time for the trip to the site is: d/v1 = 150/50 h
the time for the trip from the site is: d/v2 = 150/v2 h
the total time of the trip is: 2d/v = (2*150)/60 = 300/60 = 5 h
150/50 + 150/v2 = 5
by solving for v2 we find:
v2 = 75 mph
click here to see the step by step solution of the equation:
Bailey's average speed be on the drive back to Express King Delivery must be 75 mph.