Java - Optional loop

This is my code:

/* Linear equation student quiz
 * This program creates equations of the form ax + b = c for students to solve.
 */

import java.util.Random;
import java.util.Scanner;

public class MathFunction {
    public static void main(String[] args) {
        int a, b, c;

        double userAnswer, correctAnswer;
        int numCorrect = 0;
        Random ranNum = new Random();
        Scanner input = new Scanner(System.in);

        for (int problem = 1; problem <= 10; problem++)
        {
            a = ranNum.nextInt(2) + 1;
            b = ranNum.nextInt(41) - 20;
            c = ranNum.nextInt(41) - 20;

            System.out.print("\n"+ a + "x + " + b + " = " + c + " ... x = ");

            userAnswer = input.nextDouble();
            correctAnswer = 1.0 * (c - b) / a;

            if (userAnswer == correctAnswer)
            {
                System.out.println("Correct!");
                numCorrect =+ 1;
            }
            else
            {
                System.out.println("Sorry, correct answer is " + correctAnswer);
            }

        }//end for loop
        System.out.println("You got " + numCorrect + " out of ten.");
        System.out.println("\nWant to do 10 more questions? <y/n>");

    }//end main
}//end class

I want to be able to return to the loop if the user enters the character 'y'. The user will be prompted of this option every time they complete 10 of the math problems. Would I use a 'do-while'?