SOLUTION: Traveling at an average speed of 60 miles per hour can give better gas mileage than traveling at higher speeds. Suppose you drive from one town to another and want to average 60 mi

Algebra ->  Customizable Word Problem Solvers  -> Misc -> SOLUTION: Traveling at an average speed of 60 miles per hour can give better gas mileage than traveling at higher speeds. Suppose you drive from one town to another and want to average 60 mi      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 566769: Traveling at an average speed of 60 miles per hour can give better gas mileage than traveling at higher speeds. Suppose you drive from one town to another and want to average 60 miles per hour for the trip. Road construction on the way there reduces your average speed to 30 miles per hour. If you drive 90 miles per hour on the return trip, what is your average speed for the entire trip?
I dont think there is enough information for this.
Answer by scott8148(6628) About Me  (Show Source):
You can put this solution on YOUR website!
going ___ Tg = D / 30

returning ___ Tr = D / 90

r = d / t = 2D / (Tg + Tr) = 2D / [(D / 30) + (D / 90)] = 2D / (4D / 90) = 45