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
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#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
Exercise
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 