Problems On Probability-3

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?

8/36

3/74

7/58

9/20

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

1/6

5/12

4/9

2/5

3. In a lottery, there are 10 prizes and 25 blanks. A lottery is drawn at random. What is the probability of getting a prize?

1/10

2/5

2/7

5/7

4. 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:

21/46

25/117

1/50

3/25

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

1/2

3/4

3/8

5/16

6. Three unbiased coins are tossed. What is the probability of getting at most two heads?

3/4

1/4

3/8

7/8

7. From a pack of 52 cards, two cards are drawn together at random. What is the probability of both the cards being kings?

1/15

25/57

35/256

1/221

8. What is the probability of getting a sum 9 from two throws of a dice?

1/6

1/8

1/9

1/15

9. In a box, there are 8 red, 7 blue and 6 green balls. One ball is picked up randomly. What is the probability that it is neither red nor green?

1/3

3/4

2/5

7/6

10. A bag contains 2 red, 3 green and 2 blue balls. Two balls are drawn at random. What is the probability that none of the balls drawn is blue?

10/21

11/21

7/89

5/93

11. What is the probability that a leap year has 53 Mondays and 52 Tuesdays?

0

1/7

2/7

5/7

12. A coin tossed thrice. What is the probability that there is at least one tail ?

1/8

7/8

3/8

5/8

13. If five person sit in a row, then the probability that two persons always sit together is__

2/5

3/5

4/5

1/5

14. If three coins are tossed, the probability of getting two heads and one tail is?

5/8

3/8

1/4

3/4

15. A card is drawn from a well shuffled pack of cards, the probability of drawing a diamond or a queen is ?

17/52

15/52

4/13

9/26

16. In a pub there are 5 couples. Out of them 5 people are chosen at random. Find the probability that there are at least two couples?

5/21

5/18

9/16

16/27

17. From a pack of cards two cards are drawn at same time. The probability that the two cards are of same colour is?

14/51

15/51

16/51

None of these

18. Out of 7 persons working on a project, 3 are post graduates. If 2 are selected, what is the probability that there is at least one post graduate among them?

1/6

5/8

3/8

5/7

19. The probability that A speaks truth is 7/9 and that of B speaking truth is 5/8. What is the probability that they agree in stating the same fact?

41/72

12/35

17/35

19/35

20. 11 registers are placed at random in a shelf. The probability that a pair of registers will always be together is ________.