Permutations & Combinations · NDA previous year questions

2012 4 questions

1. Q62012 · 19 Aug 2012

   The number of permutations that can be formed from all the letters of the word 'BASEBALL' is:

   1. A.540
   2. B.1260
   3. C.3780
   4. D.5040
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   Answer: D

2. Q722012 · 19 Aug 2012

   Consider the following statements : 1. If $f(x)=x^3$ and $g(y)=y^3$ then f = g. 2. Identity function is not always a bijection. Which of the above statements is/are correct?

   1. A.1 only
   2. B.2 only
   3. C.Both 1 and 2
   4. D.Neither 1 nor 2
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   Answer: A

3. Q562012 · 15 Apr 2012

   What is the number of ways that 4 boys and 3 girls can be seated so that boys and girls alternate?

   1. A.12
   2. B.72
   3. C.120
   4. D.144
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   Answer: D

4. Q572012 · 15 Apr 2012

   If the difference between the roots of $a{x}^2+bx+c=0$ is 1, then which one of the following is correct?

   1. A.$b^2=a(a+4c)$
   2. B.$a^2=b(b+4c)$
   3. C.$a^2=c(a+4c)$
   4. D.$b^2=a(b+4c)$
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   Answer: A