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प्रश्न
The sum of first 16 terms of the AP: 10, 6, 2,... is ______.
पर्याय
–320
320
–352
–400
उत्तर
The sum of first 16 terms of the AP: 10, 6, 2,... is –320.
Explanation:
Given, AP is 10, 6, 2,...
Here,
First term a = 10,
Common difference,
d = – 4
∴ S16 = `16/2[2a + (16 - 1)d]` ...`[∵ S_n = n/2[2a + (n - 1)d]]`
= 8[2 × 10 + 15(– 4)]
= 8(20 – 60)
= 8(– 40)
= – 320
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संबंधित प्रश्न
If the sum of first m terms of an A.P. is the same as the sum of its first n terms, show that the sum of its first (m + n) terms is zero
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Which term of the AP 21, 18, 15, …… is -81?
Is 184 a term of the AP 3, 7, 11, 15, ….?
If the pth term of an AP is q and its qth term is p then show that its (p + q)th term is zero
What is the 5th term form the end of the AP 2, 7, 12, …., 47?
The sum of the first n terms of an AP is given by `s_n = ( 3n^2 - n) ` Find its
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(ii) first term and
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Find the sum of first 20 terms of an A.P. whose nth term is given as an = 5 – 2n.
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Reason (R): The sum of first n odd natural numbers is n2.
