Probability

 Defence exams are some of the most competitive exams in India, with thousands of aspirants vying for a limited number of positions. To be successful in these exams, aspirants must have a strong foundation in all subjects, including probability. Probability is a critical topic in defence exams, as it can help you analyze and interpret data in a logical and systematic manner. In this article, we will provide 20 probability questions that will help you prepare for your defence exam.

20 Probability Questions:

1.A dice is rolled twice. What is the probability of getting a sum of 7?

A. 1/6

B. 1/36

C. 1/12

D. 1/18

2.A bag contains 5 red balls, 3 blue balls, and 2 green balls. What is the probability of drawing a blue ball?

A. 1/3

B. 3/10

C. 1/5

D. 2/5

3.A coin is tossed 5 times. What is the probability of getting exactly 3 heads?

A. 5/16

B. 5/32

C. 10/32

D. 10/16

4.A box contains 6 red balls and 4 blue balls. What is the probability of drawing a red ball followed by a blue ball?

A. 3/5

B. 1/3

C. 2/5

D. 3/10

5.A deck of cards contains 52 cards. What is the probability of drawing a face card?

A. 1/4

B. 3/13

C. 1/13

D. 4/13

6 A spinner is divided into 6 equal parts numbered from 1 to 6. What is the probability of getting an odd number?

A. 1/2

B. 1/3

C. 1/6

D. 2/3

7.A committee of 5 members is to be formed from a group of 8 people. What is the probability that a specific person will be on the committee?

A. 1/4

B. 1/5

C. 3/10

D. 2/5

8.A card is drawn from a standard deck of cards. What is the probability of drawing a heart or a spade?

A. 13/52

B. 1/4

C. 1/2

D. 3/4

9.Two dice are rolled. What is the probability of getting a sum of 2 or a sum of 12?

A. 1/36

B. 1/12

C. 1/18

D. 1/6

10.A jar contains 10 marbles, 5 of which are blue and 5 of which are red. What is the probability of drawing 2 red marbles in a row without replacement?

A. 1/9

B. 1/2

C. 2/9

D. 4/9

11.A factory produces light bulbs. The probability of producing a defective bulb is 0.02. What is the probability of not producing a defective bulb?

A. 0.98

B. 0.2

C. 0.01

D. 0.05

12.A bag contains 10 red balls and 5 green balls. If two balls are drawn without replacement, what is the probability that both balls are green?

A. 1/15

B. 1/21

C. 1/21

D. 1/35

13.A coin is tossed 7 times. What is the probability of getting at least 5 heads?

A. 1/64

B. 7/64

C. 21/64

D. 57/64

14.A box contains 8 black balls and 4 white balls. What is the probability of drawing a black ball followed by another black ball without replacement?

A. 2/11

B. 4/33

C. 4/11

D. 8/33

15.A survey was conducted on a group of 1000 people. 400 people liked apple juice, 300 liked orange juice, and 200 liked grape juice. What is the probability that a person chosen at random does not like any of the three juices?

A. 1/5

B. 3/5

C. 2/5

D. 4/5

16.A bag contains 7 red balls and 5 blue balls. If three balls are drawn without replacement, what is the probability that all three balls are red?

A. 1/44

B. 1/52

C. 1/66

D. 1/78

17.A spinner is divided into 4 equal parts, colored yellow, blue, green, and red. What is the probability of getting yellow or blue?

A. 1/4

B. 1/2

C. 2/3

D. 3/4

18.A deck of cards contains 52 cards. What is the probability of drawing a red card or a face card?

A. 9/26

B. 17/26

C. 19/26

D. 23/26

19.A box contains 3 red balls, 4 blue balls, and 2 green balls. What is the probability of drawing a blue ball followed by a green ball without replacement?

A. 2/9

B. 1/6

C. 1/3

D. 4/9

20.A factory produces light bulbs. The probability of producing a defective bulb is 0.05. What is the probability of producing exactly 2 defective bulbs in a batch of 10?

A. 0.027

B. 0.203

C. 0.263

D. 0.329

Correct Answers:

1.B

2. B

3. A

4. C

5. D

6. C

7. B

8. B

9. A

10. D

11. A

12. C

13. C

14. B

15. C

16. A

17. B

18. C

19. A

20. B.