Question

Find the sum of 30th term of a given A.P. 3,9,15,21,......​

Answer 1

Answer:

1395

hope it is useful.....

Answer 2

Answer:

a=3

d=6

n=30

Sn= n / 2 × ( 2a + (n-1) × d )

Sn = 30 / 2 × ( 2 × 3 + ( 30-1 ) × 6 )

Sn = 15 ( 6 + 29 × 6 )

Sn = 15 ( 6 + 174 )

Sn = 15 × 180

Sn = 2700