Probability - Aptitude (CBSE) MCQ Questions and Solutions Class 10,9

21 . A bag contains 10 mangoes out of which 4 are rotten, two mangoes are taken out together. If one of them is found to be good, the probability that other also good is:

• 4/5
• 1/3
• 1/2
• 4/9

Answer - [ 1/3 ]

22 . A speaks truth in 60% cases B speaks truth in 70% cases. The probability that they will way say the same thing while describing a single event is:

• 0.56
• 0.54
• 0.34
• 0.43

Answer - [ 0.54 ]

23 . In a class, there are 15 boys and 10 girls. Three students are selected at random. The probability that the selected students are 2 boys and 1 girls, is:

• 45/57
• 21/46
• 67/54
• 76/54

Answer - [ 21/46 ]

24 . A basket contains 6 blue, 2 red,4 green and 3 yellow balls. If four balls are picked up at random, what is the probability that 2 are red 2 are green?

• 4/333
• 32/23
• 2/445
• 3/432

Answer - [ 2/445 ]

25 . In a class, 30% of the students offered English, 20% offered Hindi and 10% offered both. If a student is selected at random, What is the probability that he has offered English or Hindi ?

• 4/5
• 2/5
• 5/7
• 3/10

Answer - [ 2/5 ]

26 . Two dice are thrown simultaneously. What is the probability of getting two numbers whose product is even ?

• 5/6
• 3/5
• 3/4
• 5/9

Answer - [ 3/4 ]

27 . An urn contains 6 red, 4 blue, 2 green and 3 yellow marbles. If four marbles are picked up at random, what is the probability that 1 Is green, 2 are blue and 1 is red ?

• 24/455
• 3/12
• 2/14
• 45/324

Answer - [ 24/455 ]

28 . An urn contains 2 red, 3 green and 2 blue balls. If 2 balls are drawn at random, find the probability that no ball is blue.

• 10/34
• 10/21
• 3/4
• 5/6

Answer - [10/21]

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

• 7/8
• 5/12
• 1/2
• 1/10

Answer - [ 5/12 ]

30 . A box contains 10 black and 10 white balls. What is the probability of drawing 2 balls of the same colour ?

• 9/20
• 9/19
• 3/23
• 45/44

Answer - [ 9/19 ]