John goes running every morning. He can run 3 miles in 1 hour. How many miles would he be able to run in 1 and ½ hours? A. 4.5 miles B. 2 miles C. 6 miles D. 10 miles

A

Step-by-step explanation:

The easiest way to do this problem is to find out how far he can go in 1/2 hour.

If he goes 3 miles in 1 hour

he will go 3/2 miles in 1/2 hour

Now just add this onto the distance travelled in 1 hour.

3 + 3/2 = 3 + 1.5 = 4.5

The answer is A

The answer can be obtained another (perhaps better ) way.

Set up a proportion

1 hour gives 3 miles

1.5 hours gives x

1/1.5 = 3/x                Cross multiply

1*x = 1.5 * 3             Combine    

x = 4.5 miles

- both graphs increase on their domain.

- the graphs of both functions have the same x-intercept.

- neither graph has a y-intercept.