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If sn= sum(r=0)^n 1/(^"nCr) and tn=sum(r...

If `s_n= sum_(r=0)^n 1/(^"nC_r)` and `t_n=sum_(r=0)^n r/("^nC_r)` then `t_n/s_n` is equal to

A

n-1

B

n/2-1

C

n/2

D

(2n-1)/2

Text Solution

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The correct Answer is:
C
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PATHFINDER-BINOMIAL THEOREM-QUESTION BANK
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  19. If log(1-x+x^2)=a1x+a2x^2+a3x^3+……… then a3+a6+a9+……… is equal to

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