// Function to calculate discount based on the number of items function calculateDiscount(numItems) { let discountRate = 0; if (numItems > 10 && numItems <= 20) { discountRate = 0.05; // 5% discount for 11-20 items } else if (numItems > 20 && numItems <= 30) { discountRate = 0.1; // 10% discount for 21-30 items } else if (numItems > 30) { discountRate = 0.15; // 15% discount for 31 or more items } return discountRate; }