What is the sum of the first 16 terms of the given series:
$$Â 6, \frac{13}{2},7, \frac{15}{2}... $$
This series is comprised of two series.
6 , 7 , ...8Â
$$\frac{13}{2} , \frac{15}{2},...$$
16 terms of the original series will have 8 terms from both the series .
So , for first series - Sum of 8 terms
8th term = 6 +7 = 13
Sum = $$\frac{n}{2}(a + l) = \frac{8}{2}(6 + 13) = 76$$
So , for second series - Sum of 8 terms
8th term = $$\frac{13}{2} + 7 = \frac{27}{2}$$
Sum =Â $$\frac{n}{2}(a + l) = \frac{8}{2}(\frac{13}{2} + \frac{27}{2}) = 80$$
So , the answer would be option c)156.
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