This is the basic and conceptual question from Chapter name- Arithmetic Progression

Chapter number- 9

Exercise 9.4

In this question we have been given an arithmetic progression. And we have to find out how many terms are there.

CBSE DHANPAT RAI publications

Class:- 10th

Understanding CBSE Mathematics

Question 4(iii)

Given that,

A.P. 7, 13, 19, …, 205

where, a = 7 and d = a

_{2}– a_{1}= 13 – 7 = 6,nth term is 205

As we know that, to find nth term in an A.P = a + (n – 1)d

a + (n – 1)d = 205

7 + (n – 1)(6) = 205

7 + 6n – 6 = 205

6n = 205 – 1

n = 204/6

n = 34

Hence, there are 34 terms in the given A.P.