Double_t mult(Double_t a, Double_t b = 2) { // multiply a and b return a*b; } Double_t mult() { // prompt for two numbers and return the product Double_t a, b; cout << "enter a number:"; // output prompt string cin >> a; // read input cout << "enter a second number:"; // output prompt cin >> b; // read input return a*b; // return a*b }