from a handpicked tutor in LIVE 1-to-1 classes
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
☛ Check: NCERT Solutions for Class 9 Maths Chapter 15
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
☛ Related Questions:
- To know the opinion of the students about the subject statistics, a survey of 200 students was conducted. The data is recorded in the following table.Find the probability that a student chosen at randomi) likes statistics,ii) does not like it.
- Refer to Q.8, Exercise 14.2. What is the empirical probability that an engineer lives:(i) less than 7 km from her place of work?(ii) more than or equal to 7 km from her place of work?(iii) within 1/2 km from her place of work.The distance (in km) of 40 engineers from their residences are given in the table
- Eleven bags of wheat flour, each marked 5 kg, actually contained the following weights of flour (in kg):4.97 5.05 5.08 5.03 5.00 5.06 5.08 4.98 5.04 5.07 5.00Find the probability that any of these bags chosen at random contains more than 5 kg of flour.
- In Q.5, Exercise 14.2, you were asked to prepare a frequency distribution table, regarding the concentration of sulphur dioxide in the air in parts per million of a certain city for 30 days. Using the table, find the probability of the concentration of sulphur dioxide in the interval 0.12 – 0.16 on any of these days.
visual curriculum