Quantitative Aptitude
Probability
1,860 Questions
Probability Questions
C
Correct answer
Explanation
Total ways to draw 2 cards = 52C2 = (52 * 51) / 2 = 1326. Ways to draw one ace (4C1) and one king (4C1) = 4 * 4 = 16. Probability = 16 / 1326 = 8 / 663.
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1/12
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1/36
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1.18
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None of the above
A
Correct answer
Explanation
If A throws a 10, the possible outcomes for A are (4,6), (5,5), (6,4). B needs to throw more than 10 (i.e., 11 or 12). The outcomes for B to get 11 are (5,6), (6,5) and for 12 is (6,6). Total outcomes for two dice are 36. Probability = 3/36 = 1/12.
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15/18
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17/36
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5/6
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None of the above
D
Correct answer
Explanation
Sums > 9 are 10, 11, 12. Pairs: (4,6), (5,5), (6,4), (5,6), (6,5), (6,6). Total = 6 outcomes. Probability = 6/36 = 1/6.
A
Correct answer
Explanation
A standard deck has 26 red cards and 26 black cards. The probability of drawing either is (26+26)/52 = 52/52 = 1.
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$\displaystyle \frac{1}{3}$
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$\displaystyle \frac{1}{2}$
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$\displaystyle \frac{2}{3}$
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$0$
A
Correct answer
Explanation
A die has outcomes {1, 2, 3, 4, 5, 6}. Perfect squares are {1, 4}. Probability = 2/6 = 1/3.
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$\displaystyle \frac{1}{4}$
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$\displaystyle \frac{1}{3}$
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$\displaystyle \frac{1}{2}$
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$\displaystyle \frac{3}{4}$
A
Correct answer
Explanation
When tossing two coins, the sample space is {HH, HT, TH, TT}. Only one outcome, TT, results in no heads. Thus, the probability is 1/4.
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$\displaystyle \frac{1}{3}$
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$\displaystyle \frac{1}{2}$
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$\displaystyle \frac{2}{3}$
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$0$
B
Correct answer
Explanation
A die has 6 faces {1, 2, 3, 4, 5, 6}. Numbers greater than 3 are {4, 5, 6}. Probability = 3/6 = 1/2.
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$\displaystyle \frac{1}{3}$
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$\displaystyle \frac{2}{3}$
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$\displaystyle \frac{1}{2}$
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None of these.
C
Correct answer
Explanation
A standard die has 6 faces: 1, 2, 3, 4, 5, 6. The odd numbers are 1, 3, and 5, which are 3 outcomes out of 6 total possibilities. The probability is 3/6 = 1/2.
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$\displaystyle \frac{1}{52}$
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$\displaystyle \frac{1}{26}$
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$\displaystyle \frac{3}{52}$
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None of these
A
Correct answer
Explanation
There is only one Jack of Hearts in a standard deck of 52 cards. The probability is 1/52.
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$\displaystyle\frac{1}{6}$
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$1$
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$\displaystyle\frac{1}{3}$
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$\displaystyle\frac{1}{2}$
D
Correct answer
Explanation
A fair coin has two sides, head and tail. The probability of getting a tail is 1/2.
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$ \displaystyle \frac{1}{6} $
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$ \displaystyle \frac{1}{3} $
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$ \displaystyle \frac{1}{2} $
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$ \displaystyle \frac{2}{3} $
C
Correct answer
Explanation
Prime numbers on a die are 2, 3, 5. There are 3 prime numbers out of 6 faces. Probability = 3/6 = 1/2.
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$ \displaystyle \frac{1}{6} $
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$ \displaystyle \frac{2}{6} $
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$ \displaystyle \frac{4}{6} $
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$ \displaystyle \frac{5}{6} $
D
Correct answer
Explanation
A die has 6 faces {1, 2, 3, 4, 5, 6}. Numbers greater than 1 are {2, 3, 4, 5, 6}. There are 5 such numbers. Probability = 5/6.
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$ \displaystyle \frac{1}{6} $
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$ \displaystyle \frac{1}{3} $
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$ \displaystyle \frac{3}{6} $
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$ \displaystyle \frac{4}{6} $
B
Correct answer
Explanation
A die has 6 faces {1, 2, 3, 4, 5, 6}. The multiples of 3 are {3, 6}. The probability is 2/6, which simplifies to 1/3.
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$ \displaystyle \frac{1}{26} $
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$ \displaystyle \frac{1}{13} $
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$ \displaystyle \frac{3}{26} $
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None
A
Correct answer
Explanation
There are 52 cards in a deck. There are two black suits (spades and clubs). Each suit has one 10. Thus, there are two 10s of black suits. The probability is 2/52 = 1/26.
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$ \displaystyle \frac{1}{13} $
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$ \displaystyle \frac{2}{13} $
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$ \displaystyle \frac{3}{13} $
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$ \displaystyle \frac{4}{13} $
A
Correct answer
Explanation
There are 4 jacks in a standard deck of 52 cards. Probability = 4/52 = 1/13.