NDA2013MathematicsBinomial TheoremActual
What is _ r=0 ^n C(n, r) equal to?
Options
- A2^n-1
- Bn
- Cn!
- D2^n
Correct answer
D. 2^n
Step-by-step solution
aligned &(1+x)^n= ^n C ₀+ ^n C ₁ x+ ^n C ₂ x^2+ + ^n C _n x^n & for x=1 &(2)^n= ^n C ₀+ ^n C ₁+ ^n C ₂+ ^n C ₃+ + ^n C _n & _ r=0 ^n C (n, r)=(2)^n . aligned