It took Jill two hours to drive 100 miles. what was her average speed?

Average speed is 50 mph

A possible solution could be 50MPH. Meaning, "Miles Per Hour". If Jill was driving for two hours, and traveled a total of 100 miles within those two hours, then she would have had to been going 50 miles per hour. So her average speed would be 50 miles per hour.