Question

There are 15 terms in an arithmetic progression. Its first term is 5 and their sum is 390.
The middle term is
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Answer 1

Hey❤️

Total Number of Terms = 15

First term (a) = 5

Sum of the AP (Sn) = 390

$s15 = \frac{15}{2} (2 \times 5 + 14d)$

390 x 2 = 15 ( 10 + 14d )

390 x 2 = 150 + 210d

780 - 150 = 210d

630 = 210 d

d = 3

The middle term will be the 8th term,

a8 = 5 + 7d

a8 = 5 + 7(3)

a8 = 5 + 21

a8 = 26