Probability (SSC)

Total Questions: 64

31. What is the probability of getting a sum as 7 when two dice are thrown?

Correct Answer: (d)
Solution:

32. Bag A contains 2 white and 4 black balls. Bag B contains 5 white and 3 black balls. A ball is drawn from each bag, Find the probability that both are black.

Correct Answer: (c) 1/4
Solution:

33. 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?

Correct Answer: (a) 3/4
Solution:

34. I forgot the last digit of a 7-digit telephone number. If one randomly dialed the final 3 digits after correctly dialing the first four, then what is the chance of dialing the correct number ?

Correct Answer: (c)
Solution:

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

Correct Answer: (b)
Solution:

36. 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 4 or 5 ?

Correct Answer: (a)
Solution:

37. 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 ?

Correct Answer: (b)
Solution:

38. A basket contains 10 apples and 20 oranges out of which 3 apples and 5 oranges are defective. If we choose two fruits at random, what is the probability that either both are oranges or both are non defective ?

Correct Answer: (a)
Solution:

39. A bag contains cards numbered between 33 and 92. If one card is drawn from the bag, the probability that the number on the drawn card is a multiple of five :

Correct Answer: (c)
Solution:

40. A man is known to speak the truth 3 out of 8 times. He throws a dice and reports that it is a four. Find the probability that it is actually a four?

Correct Answer: (d)
Solution: