Add to MainActivity.java

Calculate price method

/**
 * Calculates the price of the order.
 * 
 * @param quantity is the number of cups of coffee ordered
 */
private void calculatePrice(int quantity) {
    int price = quantity * 5;
}

public int displayQuantityA(int quantity,int price_of_per_coffee) {
int calculate = quantity * price_of_per_coffee;
return calculate;
}

public int displayQuantityB() {
int calculate = quantity * 5;
return calculate;
}

public int displayQuantityB() {
int calculate = quantity * 5;
return calculate;
}

public void submitOrder(View view) {
String priceMessage = "Free";
displayMessage(priceMessage);
}