Download NCERT Solutions for Class 9 Maths Chapter 15 Exercise 15.1 probability in English Medium and Hindi Medium use online. NCERT Sols for Class 9 Maths and NCERT Books for class 9 in Hindi Medium as well as English Medium are given to download in PDF format.

## NCERT Solutions for Class 9 Maths Chapter 15 Exercise 15.1

If you need solutions in Hindi, Click for Hindi Medium solutions of 10 Maths Exercise 15.1

### 9 Maths Chapter 15 Exercise 15.1 in Hindi

To get the solutions in English, Click for English Medium solutions.

##### Class 9 Maths – Probability

###### Important Questions for Practice (With Answers)

- What is the sum of the probabilities of happening of an event & not happening of the event? [Answer: one]
- What could be the probability of happening of an event? [Answer: 0 ≤ P(x) ≤ 1]
- If the probability of an event to occur is 55%, then what is the probability of non-occurrence of that event? [Answer: 45%]
- What is sum of the probabilities of all the possible events of a random experiment? [Answer: one]
- What is the probability of coming a prime number on throwing of a die? [Answer: 1/2]
- A coin in tossed once, what is the probability of getting a tail? [Answer: 1/2]
- A die is tossed once, what is the probability of getting an even number? [Answer: 1/2]
- A bag contains 2 red, 3 green & 1 white ball, what is the probability that the ball picked up is black? [Answer: Zero]
- In the word MATHEMATICS, what is the probability of choosing a vowel? [Answer: 4/11]
- Out of 35 students of a class, 21 opt automobile engineering & others financial management. What is the probability of choosing a students who took financial management? [Answer: 2/5]
- During an interview for estate manager 15 candidates appeared. Out of which 8 were retired army man, 4 were retired principals & 3 others from different departments. What is the probability of selecting on army man for this post? [Answer: 8/11]
- A bag contains slips with numbers between 3 & 32. What is the probability that a slip chosen contains multiples of 4? [Answer: 7/20]
- Cards numbered from 7 to 49 are put in a box & mixed thoroughly. A card is drawn from the box, what is the probability that the number written on it is i) A prime number ii) A multiple of 7. [Answer: (i) 11/43, (ii) 7/43]
- At a traffic light on 28th April, out of 310 vehicles which crossed the light, 200 were cars, 60 were two wheeler & 50 were autos. 18 were fined for jumping the red light or not wearing of belt or helmet, 5 were fined for using car with odd number and four were left after giving warning. What is the probability that. i) A car is chosen & it bears even number. ii) a fine was given. [Answer: (i) 195/200, (ii) 23/310]
- There are 35 students in class IX A, 34 in IX B & 33th IX C. If even roll number are allotted project on chapter 2, polynomials & odd roll number are allotted chapter – 1, Number system for project. What is the probability that the student chosen i) Prepares project on chapter 1 ii) Prepares project on chapter 2. [Answer: (i) 52/102, (ii) 50/102]
- The probability of guessing the correct answer to a certain questions is x/2. If the probability of not guessing correct answer is 2/3, then find x. [Answer: 2/3]
- To know the opinion of 35 students about sixth subject as automobile engineering or financial management a survey was done. The data is recorded in the following table in favour of choosing automobile engineers.

No. of student like 20

Dislike 15

Find the probability that a student will opt (i) automobile engineering (ii) Financial management. [Answer: (i) 10/35, (ii) 22/35] - ABCD is a quadrilateral whose diagonal AC bisects it into two triangles equal in areas. Find the probability that the quadrilateral chosen has i) All the angles are right angles. ii) both the diagonals bisect each other. iii) diagonals are perpendicular to each other. iv) only one of the diagonal bisect the other. [Answer: (i) 2/5, (ii) 4/5, (iii) 3/5, (iv) 1/5]
- Read the lines carefully

Horse is horse, of course, of course.

And no one can talk to horse of course

That is, of course, unless the horse is the famous mister Id.

Find the probability of the word ‘course’ from the above stanza.

Name the word which has the same probability as the word ‘course’ has. [Answer: P(course) = 2/7, horse] - In a park, there is a right angled triangular flower bed. Its two small sides are 5 cm & 12 cm respectively. Along its three sides at a distance of 1/2 m each plants of different types are to be planted. Rose plants are to be planted along the shortest side, Marigold plants are to be planted along the longest side & sunflower plant along the third side at each of the vertex a different type of flower plant is to be planted. Find the probabilities of the following. i) Number of flower plants on the longest side. ii) number of sun flower plants. [Answer: (i) 26/60, (ii) 24/60]