Question

Sum of series.I +2+3+........+n is(a) n(n+1)/2(b) n(n+1)(c) (n+1)(n+2)/2(d) none of these​

Answer 1

Answer:

Sum of series : 1+ 2+ 3+ ........+ n

=》 n(n+1)/2.

Hence , option a is correct one.

If my answer helps you plz mark me as a brainlist .

Thankyou

_by Shivapotti