SOLUTION: The problem reads to solve: The time t required to drive a fixed distance varies inversely as the speed r. It takes 5 hr at 55mph to drive a fixed distance. How long would it ta

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: The problem reads to solve: The time t required to drive a fixed distance varies inversely as the speed r. It takes 5 hr at 55mph to drive a fixed distance. How long would it ta      Log On


   



Question 128621This question is from textbook Introductory Algebra
: The problem reads to solve: The time t required to drive a fixed distance varies inversely as the speed r. It takes 5 hr at 55mph to drive a fixed distance. How long would it take at 40mph?
Any help with this problem would be greatly appreciated.
This question is from textbook Introductory Algebra

Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
Try this:
t+=+k%2Fr Now you need to find the value of k, the constant of variation. Substitute the given values of r = 55mph and t = 5hr.
5+=+k%2F%2855%29 Multiply both sides by 55.
275+=+k Now rewrite the variation as:
t+=+275%2Fr Substitute r = 40mph
t+=+275%2F40
t+=+6.875hours or t = 6 hours and 52.5 minutes.