NCERT Solutions for Class 9 Maths Chapter 15 - Probability

What’s the probability that a cricketer will hit a boundary? How to find the number of engineers living within a 7-km radius as per the given data? Finding the answers for similar questions is easy after you practise NCERT Solutions for CBSE Class 9 Mathematics Chapter 13 Probability. TopperLearning’s textbook solutions will help you grasp the techniques to solve probability exercises from your NCERT book.

Being able to understand probability will improve your logical thinking skills and help you in calculating the answers for simple problems. Utilise our CBSE Class 9 Maths video lessons and practice tests along with our textbook solutions to revise chapter basics easily.

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Chapter 15 - Probability Exercise Ex. 15.1

Solution 1
Number of times batswoman hits a boundary = 6
Total number of balls played = 30
Ncert Solutions Cbse Class 9 Mathematics Chapter - ProbabilityNumber of times that the batswoman does not hit a boundary = 30 - 6 = 24
 
Ncert Solutions Cbse Class 9 Mathematics Chapter - Probability
Solution 2
Total number of families = 475 + 814 + 211 = 1500
 
(i) Number of families having 2 girls = 475
    Ncert Solutions Cbse Class 9 Mathematics Chapter - Probability
(ii) Number of families having 1 girl = 814
 
     Ncert Solutions Cbse Class 9 Mathematics Chapter - Probability
(iii) Number of families having no girl = 211
      Thus, the sum of all these probabilities is 1.
 
      Ncert Solutions Cbse Class 9 Mathematics Chapter - Probability
 
 
    Ncert Solutions Cbse Class 9 Mathematics Chapter - Probability
     Thus, the sum of all these probabilities is 1.


Solution 3
Number of students born in August = 6
Total number of students = 40
Ncert Solutions Cbse Class 9 Mathematics Chapter - Probability  = Ncert Solutions Cbse Class 9 Mathematics Chapter - Probability
Solution 4
Number of times 2 heads come up = 72
Total number of times the coins were tossed = 200
 
Ncert Solutions Cbse Class 9 Mathematics Chapter - Probability
Solution 5
Number of families surveyed = 2400
 
(i) Number of families earning Rs 10000 - 13000 per month and owning exactly 2 vehicles = 29
    Required probability = Ncert Solutions Cbse Class 9 Mathematics Chapter - Probability
(ii) Number of families earning Rs 16000 or more per month and owning exactly 1 vehicle = 579
     Required probability = Ncert Solutions Cbse Class 9 Mathematics Chapter - Probability
(iii) Number of families earning less than Rs 7000 per month and does not own any vehicle = 10
      Required probability = Ncert Solutions Cbse Class 9 Mathematics Chapter - Probability
(iv)  Number of families earning Rs 13000 - 16000 per month and owning     more than 2 vehicles = 25
       Required probability = Ncert Solutions Cbse Class 9 Mathematics Chapter - Probability
(v)  Number of families owning not more than 1 vehicle = 10 + 160 + 0 + 305 + 1 + 535 + 2 + 469 + 1
      + 579 = 2062
      Required probability = Ncert Solutions Cbse Class 9 Mathematics Chapter - Probability
Solution 6
Total number of students = 90
 
(i)  Number of students who obtained less than 20% marks in the test = 7
     Required probability =Ncert Solutions Cbse Class 9 Mathematics Chapter - Probability
(ii)  Number of students who obtained marks 60 or above = 15 + 8 = 23
       Required probability = Ncert Solutions Cbse Class 9 Mathematics Chapter - Probability

Solution 7
Total number of students = 135 + 65 = 200
 
(i)  Number of students who like statistics = 135
     P(student likes statistics) = Ncert Solutions Cbse Class 9 Mathematics Chapter - Probability
(ii)  Number of students who do not like statistics = 65
      P(student does not like statistics) = Ncert Solutions Cbse Class 9 Mathematics Chapter - Probability
Solution 8
Total number of engineers = 40
(i)  Number of engineers living at a distance of less than 7 km form their place of work = 9
     Required probability = Ncert Solutions Cbse Class 9 Mathematics Chapter - Probability
(ii)  Number of engineers living at a distance of more than or equal to 7 km from their place of work
       = 40 - 9 = 31
      Required probability = Ncert Solutions Cbse Class 9 Mathematics Chapter - Probability
(iii)  Number of engineers living within a distance of Ncert Solutions Cbse Class 9 Mathematics Chapter - Probability  km from her place of work = 0
       Required probability = 0

Solution 11
Total number of bags = 11
 Number of bags containing more then 5 kg of flour = 7
 Required probability = Ncert Solutions Cbse Class 9 Mathematics Chapter - Probability

Solution 12
Number days for which the concentration of sulphur dioxide was in the
interval of 0.12 - 0.16 = 2
Total number of days = 30
Required probability  =Ncert Solutions Cbse Class 9 Mathematics Chapter - Probability

Solution 13
Number of students having blood group AB = 3
Total number of students = 30
Required probability = Ncert Solutions Cbse Class 9 Mathematics Chapter - Probability