Probability · JEE Main previous year questions

2010 3 questions

1. Q42010 · 25 Apr 2010 · Shift 1

   There are two urns. Urn A has 3 distinct red balls and urn B has 9 distinct blue balls. From each urn two balls are taken out at random and then transferred to the other. The number of ways in which this can be done is

   1. A.36
   2. B.66
   3. C.108
   4. D.3
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   Answer: C

2. Q182010 · 25 Apr 2010 · Shift 1

   Four numbers are chosen at random (without replacement) from the set $\{1,2,3,\dots 20\}$. Statement - 1: The probability that the chosen numbers when arranged in some order will form an AP is $\frac{1}{85}$. Statement - 2: If the four chosen numbers form an AP, then the set of all possible values of common difference is $\{\pm 1,\pm 2,\pm 3,\pm 4,\pm 5\}$.

   1. A.Statement - 1 is true, Statement - 2 is true; Statement - 2 is not a correct explanation for Statement - 1.
   2. B.Statement - 1 is true, Statement - 2 is false.
   3. C.Statement - 1 is false, Statement -2 is true.
   4. D.Statement - 1 is true, Statement - 2 is true; Statement - 2 is a correct explanation for Statement - 1.
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   Answer: B

3. Q192010 · 25 Apr 2010 · Shift 1

   An urn contains nine balls of which three are red, four are blue and two are green. Three balls are drawn at random without replacement from the urn. The probability that the three balls have different colours is :

   1. A.$\frac{2}{7}$
   2. B.$\frac{1}{21}$
   3. C.$\frac{1}{23}$
   4. D.$\frac{1}{3}$
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   Answer: A