Write a program in C++ to display the n terms of even natural number and their sum.
Flowchart of n terms of even natural number and display their sum
C++ Source Code Of program of displaying the n terms of even natural number and their sum
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 
#include<iostream> using namespace std; int main() { int j,num,sum=0; cout<<"Input number of terms : "; cin>>num; cout<<"the even numbers are : "; j=1 ; do { cout<<2*j<<endl; sum+=2*j; j++; } while(j<=num); cout<<"The sum of numbers up to "<<num<<" terms is: "<<sum; } 
Output
Input number of terms: 5
the even numbers are:2
4
6
8
10
The sum of numbers up to 5 terms is: 30
Excercise
Find the possible mistakes in the following Shamil’s Flow Table of the program of displaying the n terms of even natural number and their sum.
Suppose user enter 5
Loop  What lines will execute?  Actual work to do 
1 time
J=1 
1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17  Sum += 2*j
Sum+=2*1; Sum+=2 
2 time
J=2

1,2,3,4,5,6,7,8,9,(10,11,12,13,14,15,16)^{2},17  Sum += 2*j
Sum+=2*2; Sum+=6 
3 time
J=3 
1,2,3,4,5,6,7,8,9,(10,11,12,13,14,15,16)^{3},17  6+=6
Sum=12 
4 time
J=4 
1,2,3,4,5,6,7,8,9,(10,11,12,13,14,15,16)^{4},17  12+=8
Sum=20 
5 time
J=5 
1,2,3,4,5,6,7,8,9,(10,11,12,13,14,15,16)^{5},17  20+=10
Sum=30 
If user enter num =0 loop still loop will execute one time
Loop  What lines will execute?  Actual work to do 
1 time
J=1 
1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17  Sum=2 
Video Lecture
Latest posts by Prof. Fazal Rehman Shamil (see all)
 The Best Tool to Test the Speed of Your Internet  May 5, 2021
 Why do we need various number systems in computer science?  April 16, 2021
 5 Best Places to Study Engineering  March 19, 2021