In Q.1, Exercise 14.2, you were asked to prepare a frequency distribution table regarding the blood groups of 30 students of a class. Use this table to determine the probability that a student of this class, selected at random, has blood group AB.
Solution:
BLOOD GROUP |
NUMBER OF STUDENTS (frequency) |
A B O AB |
9 6 12 3 |
Total |
30 |
The probability of a certain event is given by the ratio of occurrence of a particular event by the total number of events.
Probability of an event, P(E) = Number of instances that event takes place/Total number of instances
Total number of students = 30
Number of students having blood group AB = 3
Probability of students having blood group AB = (Number of students having blood group AB) / Total number of students = 3/30 = 1/10
Video Solution:
In Q.1, Exercise 14.2, you were asked to prepare a frequency distribution table regarding the blood groups of 30 students of a class. Use this table to determine the probability that a student of this class, selected at random, has blood group AB.
NCERT Solutions for Class 9 Maths - Chapter 15 Exercise 15.1 Question 13:
Summary:
The data of blood groups of 30 students is given. We have found that the probability of students having blood group AB = (Number of students having blood group AB) / Total number of students = 3/30 = 1/10