Download MARKS App - Trusted by 15,00,000+ IIT JEE & NEET aspirants! Download Now
Search any question & find its solution
Question: Answered & Verified by Expert
$\left(2^{3 n}-1\right)$ is divisible by
MathematicsBinomial TheoremCOMEDKCOMEDK 2022
Options:
  • A 6
  • B 7
  • C 8
  • D 9
Solution:
2826 Upvotes Verified Answer
The correct answer is: 7
For $n=1,2^{3 n}-1$ has value $2^3-1=7$
For $n=2,2^{3 n}-1$ has value $2^n-1=63=7 \times 9$
which is divisible by 7 not by 6 or 8 or 9 .
Hence, option (2) is correct.

Looking for more such questions to practice?

Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.