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Sequences and Series question

2022 · 26 Jul · Shift 1 · Q29
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  5. /2022 · 26 Jul · Shift 1 · Q29

Sequences and Series question

2022 · 26 Jul · Shift 1 · Q29

JEE MainMathematicsSequences and SeriesMCQ+4 / −1
Consider two G.Ps. 2, 22, 23, ..... and 4, 42, 43, .... of 60 and n terms respectively. If the geometric mean of all the 60 + n terms is (2)2258{(2)^{{{225} \over 8}}}(2)8225​, then ∑k=1nk(n−k)\sum\limits_{k = 1}^n {k(n - k)}k=1∑n​k(n−k) is equal to :
  1. A
    560
  2. B
    1540
  3. C
    1330
  4. D
    2600
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