MATHEMATICS (NDA/NA SOLVED PAPER 2022-I) (101 to 120)

Total Questions: 20

11. What is the sum of the deviations measured from the median?

The marks obtained by 51 students in a class are in AP with its first term 4 and common difference 3.

Correct Answer: (b) 0
Solution:Sum of deviations measured from the median
= Sₙ - n × Median = 51 × 79 × - 51 × 79 = 0

12. equal to?

There are 90 applicants for a job. Some of them are graduates. Some of them have less than three years experience.

Number of GraduatesNumber of Non-Graduates
At least 3 years experience189
Less than 3 years experience3627

Let G be the event that the first applicant interviewed is a graduate and T be the event that first applicant interviewed has at least 3 years experience.

Correct Answer: (b) 2/5
Solution:

13. equal to?

There are 90 applicants for a job. Some of them are graduates. Some of them have less than three years experience.

Number of GraduatesNumber of Non-Graduates
At least 3 years experience189
Less than 3 years experience3627

Let G be the event that the first applicant interviewed is a graduate and T be the event that first applicant interviewed has at least 3 years experience.

Correct Answer: (c) 4/7
Solution:

14. equal to?

There are 90 applicants for a job. Some of them are graduates. Some of them have less than three years experience.

Number of GraduatesNumber of Non-Graduates
At least 3 years experience189
Less than 3 years experience3627

Let G be the event that the first applicant interviewed is a graduate and T be the event that first applicant interviewed has at least 3 years experience.

Correct Answer: (d) 3/4
Solution:

15. What is the probability that exactly 3 out of 6 workers suffer from a disease?

The incidence of suffering from a disease among workers in an industry has a chance of (33 × 1/3)%.

Correct Answer: (d) 160/729
Solution:Let P = probability of workers which in suffering from disease.
= 1/3
q = 1 - 1/3 = 2/3

16. What is the probability that no one out of 6 workers suffers from a disease?

The incidence of suffering from a disease among workers in an industry has a chance of (33 × 1/3)%.

Correct Answer: (b) 64/729
Solution:Let P = probability of workers which in suffering from disease.
= 1/3
q = 1 - 1/3 = 2/3

17. What is the probability that at least one out of 6 workers suffer from a disease?

The incidence of suffering from a disease among workers in an industry has a chance of (33 × 1/3)%.

Correct Answer: (b) 665/729
Solution:Let P = probability of workers which in suffering from disease.
= 1/3
q = 1 - 1/3 = 2/3

P(x > 1) = 1 - P(X = 0)
= 1 - 64/729 = 665/729

18. What is the value of p?

Class0–2020–4040–6060–8080–100
Frequency17p + q32p − 3q19

The total frequency is 120. The mean is 50.

Correct Answer: (c) 27
Solution:
C.Ifixi
0–201710170
20–40p+q3030(p + 8)
40–6032501600
60–80p−3q7070p−210q
80–10019901710

(c)

19. What is the value of q?

Class0–2020–4040–6060–8080–100
Frequency17p + q32p − 3q19

The total frequency is 120. The mean is 50.

Correct Answer: (a) 1
Solution:
C.Ifixi
0–201710170
20–40p+q3030(p + 8)
40–6032501600
60–80p−3q7070p−210q
80–10019901710

(a)

20. If the frequency of each class is doubled, then what would be the mean?

Class0–2020–4040–6060–8080–100
Frequency17p + q32p − 3q19

The total frequency is 120. The mean is 50.

Correct Answer: (b) 50
Solution: