Alright guys, I am having some serious trouble with this one.

Here is one part of the project that is stumping me. I don't think I understand how this stuff works. Here is what I have to try to accomplish...

"write a program that uses the purchase class to set the following prices:

oranges, 10 for 2.99
eggs, 12 for 1.69
apples, 3 for 1.00
watermelons, 4.39 each
bagels, 6 for 3.50

Then calculate the total bill for each item for the following:

2 dozen oranges
3 dozen eggs
20 apples
2 watermelons
1 dozen bagels"

here is the purchase class that is referenced in the question...

Code :

import java.util.Scanner;
/**
Class for the purchase of one kind of item, such as 3 oranges.
Prices are set supermarket style, such as 5 for $1.25.
*/
public class Purchase
{
	private String name;
	private int groupCount; //Part of a price, like the 2 in 2 for $1.99.
	private double groupPrice; //Part of a price, like the $1.99.
	//in 2 for $1.99.
	private int numberBought; //Number of items bought.
 
	public void setName (String newName)
	{
		name = newName;
	}
 
	/**
	Sets price to count pieces for $costForCount.
	For example, 2 for $1.99.
	*/
	public void setPrice (int count, double costForCount)
	{
		if ((count <=0) || (costForCount <=0))
		{
			System.out.println ("Error: Bad parameter in setPrice.");
			System.exit (0);
		}
		else
		{
			groupCount = count;
			groupPrice = costForCount;
		}
	}
 
	public void setNumberBought (int number)
	{
		if (number <= 0)
		{
			System.out.println ("Error: Bad parameter in setNumberBought.");
			System.exit (0);
		}
		else
		{
			numberBought = number;
		}
	}
 
		/**
		Reads from the keyboard the price and number of a purchase.
		*/
		public void readInput ()
		{
			Scanner keyboard = new Scanner (System.in);
			System.out.println ("Enter name of item you are purchasing:");
			name = keyboard.nextLine ();
			System.out.println ("Enter the price of an item as 2 numbers.");
			System.out.println ("For example, 3 for $2.99 is entered as");
			System.out.println ("3 2.99");
			System.out.println ("Enter the price of an item as two numbers, now:");
			groupCount = keyboard.nextInt ();
			groupPrice = keyboard.nextDouble ();
			while ((groupCount <= 0) || (groupPrice <= 0))
			{ //Try again:
				System.out.println ("Both numbers must be positive.  Try again.");
				System.out.println ("Enter the price of an item as 2 numbers.");
				System.out.println ("For example, 3 for $2.99 is entered as");
				System.out.println ("3 2.99");
				System.out.println ("Enter the price of an item as two numbers, now:");
				groupCount = keyboard.nextInt ();
				groupPrice = keyboard.nextDouble ();
			}
			System.out.println ("Enter the number of items purchased:");
			numberBought = keyboard.nextInt ();
			while (numberBought <= 0)
			{ //Try again:
				System.out.println ("The number must be positive.  Try again.");
				System.out.println ("Enter the number of items purchased:");
				numberBought = keyboard.nextInt ();
			}
		}
 
		/**
		Displays the price and number being purchased
		*/
		public void writeOutput ()
		{
			System.out.println (numberBought + " " + name);
			System.out.println ("at " + groupCount + " for $" + groupPrice);
		}
		public String getName ()
		{
			return name;
		}
 
		public double getTotalCost ()
		{
			return (groupPrice / groupCount) * numberBought;
		}
 
		public double getUnitCost ()
		{
			return groupPrice / groupCount;
		}
 
		public int getNumberBought ()
		{
			return numberBought;
		}
}

Can someone give me some insight as to what I am supposed to be doing. I don't think I understand the question.