Answer 1

cin.get() reads one character at a time. it doesn't appropriate for that case. (Don't trust to copy paste codes!)

// Corrected version.

#include <iostream>

int main() {
int balance = 4100;
double expense;

std::cout << "How much did you spend today?"; std::cin >> expense;

double left ;
left = balance - expense;

std::cout << "You have " << left << "Rs left with you" << std::endl;
}