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 in this AP.
CBSE DHANPAT RAI publications
Class:- 10th
Understanding CBSE Mathematics
Question 4(i)
Given that,
A.P. 7, 10, 13, ….., 43
where, a = 7 and d = a2 – a1 = 10 – 7 = 3
As we know that, to find nth term in an A.P = a + (n – 1)d
a + (n – 1)d = 43
7 + (n – 1)(3) = 43
7 + 3n – 3 = 43
3n = 43 – 4
3n = 39
n = 13
Hence, there are 13 terms in the given A.P.