Mary drives 20 miles per hour and it takes 50 minutes to reach her destination. How much time would it take her to get there if she was driving 40 miles per hour?

Question

My answer: She doubled her miles per hour, so I subtracted 20 from 50 minutes and came up with 30 minutes as the answer. Is that correct?

Answer 1

d = r * t

twice the speed means half the time

Answer 2

she doubled speed so took half the time !

half of 50 minutes is 25 minutes