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The sum 7 + 77 + 777 + ... is handled by relating it to a G.P., because the given sequence:
AIs not itself a G.P.
BIs a G.P. with ratio ten
CIs an arithmetic one
DHas only one real term
Answer & Solution
Correct answer: A. Is not itself a G.P.
1. 77 divided by 7 is 11, but 777 divided by 77 is not.
2. So there is no constant ratio.
3. The terms are rewritten using powers of ten instead.
_Source: NCERT Class 11 Mathematics, Chapter 8, Sequences and Series._
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