SOLUTION: Elizabeth drove half the distance of a trip at 35 mph. At what speed would she have to drive for the rest of the distance so that the average speed for the entire trip would be 52

Algebra ->  Customizable Word Problem Solvers  -> Travel -> SOLUTION: Elizabeth drove half the distance of a trip at 35 mph. At what speed would she have to drive for the rest of the distance so that the average speed for the entire trip would be 52       Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


   



Question 955943: Elizabeth drove half the distance of a trip at 35 mph. At what speed would she have to drive for the rest of the distance so that the average speed for the entire trip would be 52 mph?
Help please!

Found 2 solutions by macston, Alan3354:
Answer by macston(5194) About Me  (Show Source):
You can put this solution on YOUR website!
Insufficient information. Please check your problem and re-post.

Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
Elizabeth drove half the distance of a trip at 35 mph. At what speed would she have to drive for the rest of the distance so that the average speed for the entire trip would be 52 mph?
---------------
d = 1/2 the total distance
r = speed of the 2nd half
---
d/35 + d/r = 2d/52
1/35 + 1/r = 1/26
(r + 35)/35r = 1/26
r+35 = 35r/26
26r + 910 = 35r
9r = 910
r = 101.111... mi/hr