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If a(1),a(2),a(3),"......" be in harmoni...

If `a_(1),a_(2),a_(3),"......"` be in harmonic progression with `a_(1)=5` and `a_(20)=25`. The least positive integer n for which `a_(n)lt0` is

A

22

B

23

C

24

D

25

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The correct Answer is:
D
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