Expert: Bobby Soltani - 9/21/2004

Question
Hello Bobby. I got this one wrong in my math test.

*Question*
On a trip, Marie drove 200 miles in 5 hours using gasoline that cost her 1.49 per gallon.

Which is greater?
1. Marie's average speed for the trip in miles per hour.

2. Marie's gas mileage for the trip in miles per gallon.

*My answer*
I know the value of 1., but I don't know that of 2. Will you help me find it? Thank you.

Kaori

Answer
Hi Kaori,

1. Marie's average speed for the trip in miles per hour.

200 miles / 5 hours = 40 miles / hour

2. Marie's gas mileage for the trip in miles per gallon.

As the problem is written, you need to how many gallons of gas she used in driving 200 miles.  Without this information, you can't solve the problem.

For instance, if the problem had said she used 10 gallons, then we could calculate that she got 200 miles / 10 gallons = 20 miles per gallon.

There is not enough information given to answer this problem.

Bobby