Permutations & Combinations · NDA previous year questions

2019 3 questions

1. Q222019 · 17 Nov 2019

   Under which one of the following conditions will the quadratic equation $x^2+mx+2=0$ always have real roots?

   1. A.$2\sqrt{3}\le m^2<8$
   2. B.$\sqrt{3}\le m^2<4$
   3. C.$m^2\ge 8$
   4. D.$m^2\le \sqrt{3}$
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   Answer: C

2. Q212019 · 21 Apr 2019

   From 6 programmers and 4 typists, an office wants to recruit 5 people. What is the number of ways this can be done so as to recruit at least one typist?

   1. A.209
   2. B.210
   3. C.246
   4. D.242
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   Answer: C

3. Q222019 · 21 Apr 2019

   How many three-digit even numbers can be formed using the digits 1, 2, 3, 4 and 5 when repetition of digits is not allowed?

   1. A.36
   2. B.30
   3. C.24
   4. D.12
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   Answer: C