Question

the sum of the series 32 + 62 + 92 + 122 + ... up to n terms is sn then s20 is equal to

Answer 1

this is an ap.. with
a=32
d,=30
$s |n| = \frac{n}{2} (64 + (n - 1)(30)) \\ s |n| = \frac{n}{2} (30n + 34).......ans \\ s |20| = 10(600 + 34) \\ s |20| = 6340$