50 minutes doesn't matter at all, so don't pay attention to it.
You know that 36 miles is 48% of the distance, so you need to find out how many miles equals 100%.
You can write it as a ratio:
36 is to what as 48 is to 100.
Write it as fractions, and set them equal to each other.
36/x = 48/100
(cross multiply)
48x = 3600
(isolate the x, divide both sides by 48)
Your answer is 45 miles!
