A basic and conceptual question from arithmetic progression chapter in which we have been asked to find the 20th term of the series 9,13,17,21,......
Book – RS Aggarwal, Arithmetic Progression, chapter 5A, question no 2(i)
Share
Lost your password? Please enter your email address. You will receive a link and will create a new password via email.
Given AP is 9,13,17,21,....
Here, first term =a=9
Common difference=d=13−9=4
nth term is given by,
an=a+(n−1)d
For 20th term put n=20.
a20=9+(20−1)4
=85.