Question

Find the sum of the first 16 terms of the A.P.10,6,2,..

Answer 1

Solution:-

Given A.P terms are 10, 6, 2,...

common Difference = 6-10 = -4

Sum of 16 terms $=\frac{16}{2}[2\times 10+(16-1\left)\right(-4\left)\right]$

$=8[20-60]$

$=8[-40]=-320$