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 its 10th term.
CBSE DHANPAT RAI publications
Class:- 10th
Understanding CBSE Mathematics
Question 1(iv)
Given that,
A. P. is – 40, -15, 10, 35, ……….
First term (a) = -40,
Common difference (d) = Second term – fast term
d = -15 – (- 40) = 40 – 15 = 25
As we know that, to find nth term in an A.P = a + (n – 1)d
Therefore, 10th term of A. P. = -40 + (10 – 1)25
= – 40 + 9.25 = – 40 + 225 = 185
Hence 10th term of the A.P is 185