Binomial Theorem · NDA previous year questions

2020 5 questions

1. Q22020 · 6 Sept 2020

   The term independent of $x$ in the binomial expansion of ${\left(\frac{2}{x^2}-\sqrt{x}\right)}^{10}$ is equal to

   1. A.180
   2. B.120
   3. C.90
   4. D.72
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   Answer: A

2. Q32020 · 6 Sept 2020

   If $(1+2x-x^2{)}^6=a_0+a_{1}x+a_2{x}^2+\dots +a_{12}{x}^{12}$, then what is $a_0-a_1+a_2-a_3+a_4-\dots +a_{12}$ equal to?

   1. A.32
   2. B.64
   3. C.2048
   4. D.4096
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   Answer: B

3. Q42020 · 6 Sept 2020

   If $C(20,n+2)=C(20,n-2)$, then what is $n$ equal to?

   1. A.18
   2. B.25
   3. C.10
   4. D.12
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   Answer: C

4. Q492020 · 6 Sept 2020

   What is the sum of the last five coefficients in the expansion of $(1+x{)}^9$ when it is expanded in ascending powers of $x$?

   1. A.256
   2. B.512
   3. C.1024
   4. D.2048
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   Answer: A

5. Q1102020 · 6 Sept 2020

   If $\sum x_i=20$, $\sum x_i^2=200$ and $n=10$ for an observed variable $x$, then what is the coefficient of variation?

   1. A.80
   2. B.100
   3. C.150
   4. D.200
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   Answer: D