Sequences and Series 2 Question 4
4. If the sum and product of the first three terms in an AP are 33 and 1155, respectively, then a value of its 11 th term is
(2019 Main, 9 April II)
(a) 25
(b) -36
(c) -25
(d) -35
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Answer:
Correct Answer: 4. (b)
Solution:
- Let first three terms of an
So,
[given sum of three terms
So the first three terms of the AP are either 7, 11, 15 or
So, the 11 th term is either
or
Key Idea Use the formula of sum of first
Given AP, is
[where,
(given)
Therefore,
