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Inserting two numbers between 3 and 81 so the sequence is a G.P. gives:
A6 and 9
B27 and 54
C12 and 36
D9 and 27
Answer & Solution
Correct answer: D. 9 and 27
1. 81 is the fourth term, so r cubed is 27.
2. That gives r equal to 3.
3. The inserted numbers are 9 and 27.
_Source: NCERT Class 11 Mathematics, Chapter 8, Sequences and Series._
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