Help with my program I'm new...

I have a program to write: Wrtie a class MPG, which has two instance variables miles and gallons, three instance methods printmpg(), setmiles(float m) and setgallons (float g) and aconstructor MPG (float m, float g).
(i) printMPG() - calculate and prints the miles per gallon based on the values held in the instance variables miles and gallons - mpg=miles/gallons.
(ii)set miles (float m) - set the miles i.e set miles to the value of the parameter passed
(iii) setgallons(float g) - set the gallons i.e sets gallons to the value of the parameter passed
(iv) MPG (Float m, float g) - the constructor which sets the instance variable miles and gallons.

This is what I have and I dont know what to do after. I am completely lose. Please help someone...

Code :

---

import java.io;
class MPG
{
   //instance variable
     int miles;
     int gallons;
   //constructor
    MPG (float m, float g)
    {
      miles=m; gallons=g;
      }
        //methods
        double PrintMPG()
        {
          return miles/gallons;
         }

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I am really really lost.. Please someone help. I know this is a simple program... Thanks...

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