SOLUTION: The time t required to drive a fixed distance varies inversely as the speed r. It takes 5 hours at 55 mph to drive a fixed distance. How long would it take at 40 mph?

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: The time t required to drive a fixed distance varies inversely as the speed r. It takes 5 hours at 55 mph to drive a fixed distance. How long would it take at 40 mph?      Log On


   

Question 168280This question is from textbook Introductory Algebra
: The time t required to drive a fixed distance varies inversely as the speed r. It takes 5 hours at 55 mph to drive a fixed distance. How long would it take at 40 mph? This question is from textbook Introductory Algebra

Answer by jojo14344(1513) About Me  (Show Source):
You can put this solution on YOUR website!
Since t varies inversely to r, it follows:
t%5B1%5Dr%5B1%5D=t%5B2%5Dr%5B2%5D
where----system%28t%5B1%5D=5hrs%2Ct%5B2%5D=t%5B2%5D%2Cr%5B1%5D=55mph%2Cr%5B2%5D=40mph%29
Continuing,
5%2A55=t%5B2%5D%2A40
275%2F40=t%5B2%5Dcross%2840%29%2Fcross%2840%29
highlight%28t%5B2%5D=6.875hrs%29 ---> 6 hrs & 52.5 mins
*It make sense for t to go up, since r goes down,Varies Inversely.
Thank you,
Jojo