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:

(a) n(n+1)/2

Step-by-step explanation:

It is a formula in special series

Answer 2

this series is in resistance

formula of that isRs=R1+R2+R3+...+Rn

so the answer d.none of this is correct