Answer:
#include<iostream>
using namespace std;
int main()
{
 int num=0,sum=0;
 cout<<"Insert Number to find sum of mutiples.";
 cin>>num;
 int temp=num;
 if(num>0){
  sum+=num;
 while(num<100){
    num+=temp;
 sum+=num;
    Â
 }
 cout<<"Sum of Multiples is ="<<sum<<endl;
 }else{
 return 0;
 }
return 0;
}
Explanation:
This code is written in c++. Written by Saad-Ur-Rehman.