Question

Eric's mother drives to work in 20 minutes when driving at her usual speed. When traffic is bad,she drives 10 miles per hour slower, and the trip takes 10 minutes longer. What is Eric's mother's usual speed

Answer 1

Pretty Sure it’s 20mph

Explanation:

X/20=x-10/30

30x=20x-200

30x=20x-200

-20x

10x=-200

Divied by ten on both sides.

x=-20

20mph