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For a sequence `{a_n}, a_1 = 2` and `a_(n+1)/a_n=1/3` then `sum_(r=1)^20 a_r` is

A

`(20)/(2)[4+19xx3]`

B

`3(1-(1)/(3^20))`

C

`2(1-3^20)`

D

None of these

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The correct Answer is:
B
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MOTION-SEQUENCE & SERIES -Exercise -1 Objective Problems /JEE Main Section -A : AP
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