Lost your password? Please enter your email address. You will receive a link and will create a new password via email.
Please briefly explain why you feel this question should be reported.
Please briefly explain why you feel this answer should be reported.
Please briefly explain why you feel this user should be reported.
The table given below shows the marks obtained by 30 students in a test.
| Marks (Class interval) | 1-10 | 11-20 | 21-30 | 31-40 | 41-50 |
| Number of students (Frequency) | 7 | 10 | 6 | 4 | 3 |
Out of these students, one is chosen at random. What is the probability that the marks of the chosen student
(i) are 30 or less?
(ii) are 31 or more?
(iii) lie in the interval 21 – 30?
The table given below shows the marks obtained by 30 students in a test.
| Marks (Class interval) | 1-10 | 11-20 | 21-30 | 31-40 | 41-50 |
| Number of students (Frequency) | 7 | 10 | 6 | 4 | 3 |
Out of these students, one is chosen at random. What is the probability that the marks of the chosen student
(i) are 30 or less?
(ii) are 31 or more?
(iii) lie in the interval 21 – 30?
It is given that
Total number of students = 30
(i) We know that
Probability that the marks of the chosen students are 30 or less = (7 + 10 + 6)/ 30
So we get
Probability that the marks of the chosen students are 30 or less = 23/30
(ii) We know that
Probability that the marks of the chosen students are 31 or more = (4 + 3)/30
So we get
Probability that the marks of the chosen students are 31 or more = 7/30
(iii) We know that
Probability that the marks of the chosen students lie in the interval 21 – 30 = 6/30
So we get
Probability that the marks of the chosen students lie in the interval 21 – 30 = 1/5