NDA 2026
- Exam
- NDA
- Year
- 2026
- Subject
- Mathematics
- Chapter
- Binomial Theorem
NDA 2026 · Mathematics · Binomial Theorem
Passage: Let u be a positive integer and f be a real number lying...
Passage: Let be a positive integer and be a real number lying between . Further, \left(\sqrt{2}+1\right)^{10}=u+f.
Question: What is the value of ?
Question: What is the value of ?
Options
- A
- B
- C
- D
Correct answer
B.
Step-by-step solution
Given and .
Adding both equations:
Expanding using the binomial theorem:
The right hand side is an even integer. Let it be .
Since and are integers, must be an integer.
We are given .
Also, .
Adding the inequalities for and :
Since is an integer strictly between and , the only possible value is .
Therefore, .
Answer:
Adding both equations:
Expanding using the binomial theorem:
The right hand side is an even integer. Let it be .
Since and are integers, must be an integer.
We are given .
Also, .
Adding the inequalities for and :
Since is an integer strictly between and , the only possible value is .
Therefore, .
Answer: