Question

The sum of 20 term of an ap 1,4,7,10,....is

Answer 1

Answer:

Why is it said that the "knowledge is nothing without the presence of mind?"

Answer 2

Step-by-step explanation:

a=1

d=3

Sn=n/2[a+(n-1)d]

=20/2[1+(20-1)3]

=10[1+19×3]

=10×58

=580

the sum of 20terms is 580

hope it help ☺☺