Alice walks on a straight line at four miles per hour. Two hours after she begins walking, Bob runs after her at a rate of six miles per hour. How fast (in miles per hour) is Bob gaining on Alice?

Answer 1

6-4

Answer 2

You posted this yesterday
http://www.jiskha.com/display.cgi?id=1476153606

Why did you post it again today?

Answer 3

I trust Steve