Expression : 13 + 14 ……. 20
The above series is an A.P. with first term, $$a=13$$, last term, $$l=20$$ and common difference, $$d=1$$
=> Number of terms be = $$n=(20-13)+1=8$$
Sum of A.P. = $$\frac{n}{2}(a+l)$$
= $$\frac{8}{2}(13+20)$$
= $$4\times33=132$$
=> Ans - (C)
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