Part A: A runner completes the ¼ mile in 2.25 min. With what speed was the runner traveling?

Part B: How fast does a person have to run to complete the mile in 6 minutes?

2.25 min = 2.25/60 hours

= .0375 hours

so (1/4) mile/ 2.25 min
= (.25/.0375) miles/hour
= 20/3 mph or 6 2/3 mph

Part B

1 mile/6 minutes = x miles/60 minutes
6x = 60
x = 10
So he has to run at 10 mph