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Consider the sequence 1,2,2,3,3,3,"……", ...

Consider the sequence `1,2,2,3,3,3,"……",` where n occurs n times that occuts as 2011th rerms is

A

61

B

62

C

63

D

64

Text Solution

Verified by Experts

The correct Answer is:
C

The last 4 occurs as `1+2+3+4+=10th` term. The last n occurs as `((n(n+1))/(2))^(th)` term, the last 62 occurs as
`((63xx63)/(2))^(th)=1953rd` term and the last 63 occurs as
`((64xx64)/(2))^(th)=2016th` term.
`:. 63` occurs from 1954th term to 2016th term.
Hence, `(2011)^(th)` term os 63.
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