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Question: Answered & Verified by Expert
0.2+0.22+0.222+ upto n terms is equal to
MathematicsSequences and SeriesJEE Main
Options:
  • A 29-2811-10-n
  • B n191-10-n
  • C 29n-191-10-n
  • D 29
Solution:
2926 Upvotes Verified Answer
The correct answer is: 29n-191-10-n
0.2+0.22+0.222+...n terms

=20.1+0.11+0.111+nterms

=2110+11100+1111000+nterms

=29910+99100+9991000+n  terms

=291-110+1-1100+1-11000+n  terms

=29n-110+1100+11000+n

=29n-1101-110n1-110

=29n-110×109.10n-110n

=29n-191-10-n

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