MPG mathematical calculations and imputing data

I'm trying to do problem 1 from chapter 3.

It says: "Create a world in which the user is asked for the number of gallons of fuel his or her car can hold, and the number of miles that he or she can drive on a full tank. Use variables to hold these values. You should also have a variable to hold the car's miles-per-gallon (MPG). Calculate the MPG with the following forumla:

MPG=miles/gallons

The world should have a person and a car. The initial setup the car should be positioned off-camera. After the data is entered, the person should approach the camera and the car should drive into view and stop in front of the camera. The person should then say a message indicating the car's MPG, as calculated from the data entered by the user. Then the car should drive away, to a position off camera. "

I don't know how to begin this problem. Is it possible for someone to walk me threw it? I have no idea how to make the character say the MPG.

Thank You

[TauTrumpsPi]

In the methods, there should be a "say" method.

Ask for input by using the "ask user for a number" function.