Question 31770
Let's see what we know:
Mary's Distance = 285 miles
Mary's Speed = 57mph
Mary's Time = x

Tiffany's Distance = 220 miles
Tiffany's Speed = w mph
Tiffany's Time = x

The reason both Tiffany and Mary's time = x, is because they both got home at the same time so they must have taken the same time to get home. duh!

Distance = Speed x Time

Time = Distance divided by Speed

Mary's Time = 285 divided by 57

{{{x = 285/57}}} -->This is the time both of them took to get home

This is therefore, the time Tiffany took to get home as well.

Distance = Speed x Time

Speed = Distance divided by time

Tiffany's Speed = Tiffany's Distance divided by Tiffany's Time

{{{w = (220/(285/57))}}}

w =44 mph!