One of the most important and exam oriented question from Chapter name- Arithmetic Progression
Class 10th
Chapter number- 9
Exercise :- 9.6
This type of question has been asked in previous years exams.
In this question we have been given that the first term of an A.P. is 2 and the last term is 50. The sum of all these terms is 442.
Now we have to find the common difference.
CBSE DHANPAT RAI publication
CBSE Mathematics Class 10th
Question 16
Given A.P. has first term(a) = 2, last term(an) = 50 and sum(Sn) = 442.
We know sum of n terms of an A.P. is given by Sn = n[a + an]/2.
=> 442 = n[2 + 50]/2
=> 26n = 442
=> n = 17
Also, we know nth term of an A.P. is given by, an = a + (n − 1)d. So, we get,
=> 50 = 2 + (17 − 1)d
=> 16d = 48
=> d = 3
Hence, the common difference of the A.P. is 3.