Question

sum of all terms of the series - 3, - 1, 3, 5 upto 51 is​

Answer 1

a=-3

d=2

n=51

Sn=n/2(2a+(n-1)d)

=51/2(2*(-3)+50*2)

=51/2(-6+100)

=51/2*94

=2397

Hope this helps.