The above frequency distribution table represents 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. - Mathematics

Advertisements
Advertisements
Blood Group Number of Students
A 9
B 6
AB 3
O 12
Total 30

The above frequency distribution table represents 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.

Advertisements

Solution

Number of students having blood group AB = 3

Total number of students = 30

Hence, required probability, `P = 3/30 = 1/10`

 

  Is there an error in this question or solution?
Chapter 15: Probability - Exercise 15.1 [Page 285]

APPEARS IN

NCERT Mathematics Class 9
Chapter 15 Probability
Exercise 15.1 | Q 13 | Page 285

Video TutorialsVIEW ALL [1]

RELATED QUESTIONS

1500 families with 2 children were selected randomly, and the following data were recorded:-

Number of girls in a family 2 1 0
Number of families 475 814 211

Compute the probability of a family, chosen at random, having

(i) 2 girls (ii) 1 girl (iii) No girl

Also check whether the sum of these probabilities is 1.


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, 5.00

Find the probability that any of these bags chosen at random contains more than 5 kg of flour.


Two coins are tossed simultaneously 500 times with the following frequencies of different outcomes:
Two heads: 95 times
One tail: 290 times
No head: 115 times
Find the probability of occurrence of each of these events.


Given below is the frequency distribution table regarding the concentration of sulphur dioxide in the air in parts per million of a certain city for 30 days.

Conc. of SO2 0.00-0.04 0.04-0.08 0.08-0.12 0.12-0.16 0.16-0.20 0.20-0.24
No. days: 4 8 9 2 4 3
 

Find the probability of concentration of sulphur dioxide in the interval 0.12-0.16 on any of these days.


Define a trial.

 

In a football match, Ronaldo makes 4 goals from 10 penalty kicks. The probability of converting a penalty kick into a goal by Ronaldo, is


In a sample study of 642 people, it was found that 514 people have a high school certificate. If a person is selected at random, the probability that the person has a high school certificate is ______.


80 bulbs are selected at random from a lot and their life time (in hrs) is recorded in the form of a frequency table given below:

Life time (in hours) 300 500 700 900 1100
Frequency 10 12 23 25 10

One bulb is selected at random from the lot. The probability that its life is 1150 hours, is ______.


Over the past 200 working days, the number of defective parts produced by a machine is given in the following table:

Number of
defective parts
0 1 2 3 4 5 6 7 8 9 10 11 12 13
Days 50 32 22 18 12 12 10 10 10 8 6 6 2 2

Determine the probability that tomorrow’s output will have no defective part


A recent survey found that the ages of workers in a factory is distributed as follows:

Age (in years) 20 – 29 30 – 39 40 – 49 50 – 59 60 and above
Number of workers 38 27 86 46 3

If a person is selected at random, find the probability that the person is having age from 30 to 39 years


Share
Notifications



      Forgot password?
Use app×