Amanda drove 936 miles in 13 hours. at the same rate, how long would it take her to drive 648 miles?

You need to use the equation D=RT

First you need to solve for the rate before you can see how long it takes her to drive 648 miles.

936 miles=Rate times (13 hours)

Rate = 72 miles/hour

Since the rate is the same, you can solve for time.

D=rt 648 = (72) (T). Time=9 hours