NDA 2015
- Exam
- NDA
- Year
- 2015
- Subject
- Mathematics
- Chapter
- Binomial Theorem
NDA 2015 · Mathematics · Binomial Theorem
What is (∑_ r=0 ^1 n+r n ) equal to?
What is (\sum_{r=0}^1\binom{n+r}{n}) equal to?
Options
- A(\binom{n+2}{1})
- B(\binom{n+3}{n})
- C(\binom{n+2}{n})
- D(\binom{n+2}{n+1})
Correct answer
A. (\binom{n+2}{1})
Step-by-step solution
(\sum_{r=0}^1\binom{n+r}{n}=\binom{n}{n}+\binom{n+1}{n}=1+(n+1)=n+2=\binom{n+2}{1})