Question

20. Find the 8th term from the end of the AP 7, 10, 13, ..., 184.
[CBSE 2005​

Answer 1

a=7

d=10-7=3

8 th term=a+7d

=7+(7×3)

=7+21

=28

Answer 2

an=a+(n-1)d=184
=7+(n-1)3=184
(n-1)3=177
n-1=59
n=60
53rd term is the 8th term from last

a53= a+52(d)

7+52(3)
7+156
=163