n plus 15.n plus 15.n plus 15.n plus 15.
3n.
One lot of them.
The answer is n + 1610.
N=0
n plus 15.n plus 15.n plus 15.n plus 15.
They have n in common.
3n.
One lot of them.
2 plus n is the true one, but 1 plus n is not?
n = 28
(n2 + n)/2 1+2+3+4+5+n= 15+n
The answer is n + 1610.
N=0
if (n%2==0) sum=n/2*(n+1); else sum=(n+1)/2*n;
-n + 4(n + 1) = 3n+4
(n*n)+n