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 = a2 – a1 = 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.