NDA2023MathematicsBinomial TheoremActual
A set S contains (2n +1) elements. There are 4096 subset of S which contain at most n elements. what is n equal to
Options
- A5
- B6
- C7
- D8
Correct answer
B. 6
Step-by-step solution
aligned & Since, n ( s )=2 n +1 & Now, ^ 2 n +1 C ₀+ ^ 2 n +1 C ₁+ ^ 2 n +1 C ₂+ .+ ^ 2 n +1 C _ n + & ^ 2 n +1 C _ n +1 + ^ 2 n +1 C _ n +2 + . .+ ^ 2 n +1 C _ 2 n +1 =2^ 2 n +1 & 2 ( ^ 2 n +1 C ₀+ ^ 2 n +1 C ₁+ .+ ^ 2 n +1 C _ n )=2^ 2 n +1 =4096 & 2^ 2 n =2¹² 2 n =12 n =6 aligned