the sum of 1 plus 9 is 10 because 1+9
The sum is: 8
The sum is 1511.
The sum of the numbers given is 31. 1 + 2 + 4 + 8 + ... + 2n = 2n+1 - 1
2
2
Sum = 79*(79+1)/2 = 79*80/2 = 3160
if (n%2==0) sum=n/2*(n+1); else sum=(n+1)/2*n;
The sum of -1 and -1 is -2.
1+0+3 is the digit sum of 103
87
5050