During execution of main(), how many user-defined methods are called? a) public static double calcTax(double cost) { return cost * 0.15; } b) public static double calcShippingCost(double weight) { double cost; if(weight < 10) { cost = 10.0; }else{ cost = 15.5; } cost = cost + calcTax(cost); return cost; } c) public static void main(String args[]) { double cost1; double cost2; cost1 = calcShippingCost(7.5); cost2 = calcShippingCost(17.5); }

b) public static double calcShippingCost(double weight) { double cost; if(weight < 10) { cost = 10.0; }else{ cost = 15.5; } cost = cost + calcTax(cost); return cost; }

The method is called twice with arguments 7.5 and 17.5 respectively.

Explanation:

The Java program defines three user methods including the main. In the main, the calShippingCost method is called twice with 7.5 and 17.5 respectively to return double number values to cost1 and cost2.