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  • Question
  • Two dice are tossed. The probability that the total score is a prime number is:


  • Options
  • A. 5/12
  • B. 1/6
  • C. 1/2
  • D. 7/9

  • Correct Answer
  • 5/12 

    Explanation

    Clearly, n(S) = (6 x 6) = 36.

    Let E = Event that the sum is a prime number.

    Then E= { (1, 1), (1, 2), (1, 4), (1, 6), (2, 1), (2, 3), (2, 5), (3, 2), (3, 4), (4, 1), (4,3),(5, 2), (5, 6), (6, 1), (6, 5) }

    n(E) = 15.

    P(E) = n(E)/n(S) = 15/36 = 5/12.


  • Probability problems


    Search Results


    • 1. Tickets numbered 1 to 20 are mixed up and then a ticket is drawn at random. What is the probability that the ticket drawn has a number which is a multiple of 3 or 5?

    • Options
    • A. 1/2
    • B. 3/5
    • C. 9/20
    • D. 8/15
    • Discuss
    • 2. In a lottery, there are 10 prizes and 25 blanks. A lottery is drawn at random. What is the probability of getting a prize?

    • Options
    • A. 2/7
    • B. 5/7
    • C. 1/5
    • D. 1/2
    • Discuss
    • 3. A man and his wife appear in an interview for two vacancies in the same post. The probability of husband's selection is (1/7) and the probability of wife's selection is (1/5). What is the probability that only one of them is selected ?

    • Options
    • A. 2/7
    • B. 1/7
    • C. 3/4
    • D. 4/5
    • Discuss
    • 4. Two cards are drawn at random from a pack of 52 cards.what is the probability that either both are black or both are queen?

    • Options
    • A. 52/221
    • B. 55/190
    • C. 55/221
    • D. 19/221
    • Discuss
    • 5. A problem is given to three students whose chances of solving it are 1/2, 1/3 and 1/4 respectively. What is the probability that the problem will be solved?

    • Options
    • A. 1/4
    • B. 1/2
    • C. 3/4
    • D. 7/12
    • Discuss
    • 6. What is the probability of getting 53 Mondays in a leap year?

    • Options
    • A. 1/7
    • B. 3/7
    • C. 2/7
    • D. 1
    • Discuss
    • 7. A bag contains 4 white, 5 red and 6 blue balls. Three balls are drawn at random from the bag. The probability that all of them are red, is:

    • Options
    • A. 2/91
    • B. 1/22
    • C. 3/22
    • D. 2/77
    • Discuss
    • 8. Two dice are thrown together .What is the probability that the sum of the number on the two faces is divided by 4 or 6.

    • Options
    • A. 7/18
    • B. 14/35
    • C. 8/18
    • D. 7/35
    • Discuss
    • 9. A letter is takenout at random from 'ASSISTANT' and another is taken out from 'STATISTICS'. The probability that they are the same letter is :

    • Options
    • A. 35/96
    • B. 19/90
    • C. 19/96
    • D. None of these
    • Discuss
    • 10. In a class, there are 15 boys and 10 girls. Three students are selected at random. The probability that 1 girl and 2 boys are selected, is:

    • Options
    • A. 21/46
    • B. 1/5
    • C. 3/25
    • D. 1/50
    • Discuss


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