Answer and Explanation:
It's actually pretty easy, keep in mind you need to import the following libraries at the beginning of the code:
#include <iostream>
#include <stdio.h>
#include <math.h>
using namespace std;
int main(){
int age;
int age_m;
cout<<("enter your age");
cin>>age;
age_m=age*12;
cout<<("Your age in months is: ");
cout<<age_m;
}