If $n$ be odd or even, then the sum of $n$ terms of the series $1 - 2 + $ $3 - $$4 + 5 - 6 + ......$ will be
If $n$ be odd or even, then the sum of $n$ terms of the series $1 - 2 + $ $3 - $$4 + 5 - 6 + ......$ will be
- A
$ - \frac{n}{2}$
- B
$\frac{{n - 1}}{2}$
- C
$\frac{{n + 1}}{2}$
- D
(a) and (c) both
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