This is the basic and conceptual question from Chapter name- Arithmetic Progression
Chapter number- 9
Exercise 9.6
In this question we have been given an arithmetic progression. And we have to find its sum upto 36 terms.
CBSE DHANPAT RAI publications
Class:- 10th
Solutions of CBSE Mathematics
Question 1(viii)
Given A.P. has first term(a) = -26,
Common difference(d) = -24 – (-26) = 2
and number of terms(n) = n.
So, Sum of A.P. = S36 = n[2a + (n – 1)d] / 2
= 36[2(-26) + (36 – 1)2]/2
= 18[-52 + 70] = 324
Hence, the sum of the first 36 terms of A.P. is 324.