How long will it takes us to get to the airport?

Question

On the way to the airport on December 8, 2011, my wife's car hit a huge hole in a construction area, damaging the front right wheel. The temporary tire forced us to decrease our average speed by 15 miles per hour. If the 39- mile drive usually takes us 45 minutes, how much time should we have budgeted for the drive home from the airport?

Answer 1

you should use rate*time=distance.

 

so the normal ride you would plug in r*(3/4) = 39....so r = 52 miles per hour. notice that I had to change 45 minutes to 3/4 of an hour to get mile per hour as my units.

 

So since you blew out your tire and are travelling at 15mph less, that would be a new rate of 52-15 = 37mph

 

We can now plug the new rate in to get 37*t = 39...so t=39/37 = 1.054 hrs. or 1hr and 3 minutes and 15 seconds....approximately.

 

Hope this helped.