Find the sum of the first 50 terms of the sequence 2,4,6,8........
That is twice the sum of 1+2+3+...+50
For 1+2+...+N, the sum is N(N+1)/2
The sum is therefore 2*[50*51)/2) = 2550
That is twice the sum of 1+2+3+...+50
For 1+2+...+N, the sum is N(N+1)/2
The sum is therefore 2*[50*51)/2) = 2550