Table of Contents

Toggle## Class 8, Maths, Chapter 5, Exercise 5.3, Solutions

**Q.1. List the outcomes you can see in these experiments.**

**(a) Spinning a wheel **

**(b) Tossing two coins together**

**Ans: **(a) Outcomes = A, B, C, D

(b) Tossing two coins together

**Q.2. When a die is thrown, list the outcomes of an event of getting**

**(i) (a) a prime number (b) not a prime number.**

**(ii) (a) a number greater than 5 (b) a number not greater than 5.**

**Ans:**

**(i) **(a) a prime number = 2,3,5

(b) not a prime number = 1,4,6

**(ii) **(a) a number greater than 5 = 6

(b) a number not greater than 5 = (1,2,3,4,5)

**Q.3. Find the.**

**(a) Probability of the pointer stopping on D in (Question 1-(a))?**

**(b) Probability of getting an ace from a well shuffled deck of 52 playing cards?**

**(c) Probability of getting a red apple. (See figure below)**

**Ans: ****(a) **total number of evets or parts = 5

Number of favourable outcomes = 1

$=\frac{Favourable\,\,outcome}{Total\,\,parts}=\frac{1}{5}$

**(b) **total number of evets = 52

Number of favourable outcomes = 4 (there are 4 aces in a pack of cards)

** $=\frac{Favourable\,\,outcome}{Total outcomes\,\,}=\frac{4}{52}=\frac{1}{13}$**

**(c) **total number of evets = 6

Number of favourable outcomes = 4

** $=\frac{Favourable\,\,outcome}{Total events\,\,}=\frac{4}{7}$**

**Q.4. Numbers 1 to 10 are written on ten separate slips (one number on one slip), kept in a box and mixed well. One slip is chosen from the box without looking into it. What is the probability of .**

**(i) getting a number 6?**

**(ii) getting a number less than 6?**

**(iii) getting a number greater than 6?**

**(iv) getting a 1-digit number?**

**Ans: **

**Total number of events = 10**

(i) Getting a number 6: $=\frac{Favourable\,\,outcome}{Total\,\,}=\frac{1}{10}$

(ii) getting a number less than 6: $=\frac{Favourable\,\,outcome}{Total\,\,}=\frac{5}{10}=\frac{1}{2}$

(iii) getting a number greater than 6 : $=\frac{Favourable\,\,outcome}{Total\,\,}=\frac{4}{10}=\frac{2}{5}$

(iv) getting a 1-digit number: $=\frac{Favourable\,\,outcome}{Total\,\,}=\frac{9}{10}$

**Q.5. If you have a spinning wheel with 3 green sectors, 1 blue sector and 1 red sector, what is the probability of getting a green sector? What is the probability of getting a non blue sector?**

**Ans:**

Total number of events = 5 (because there are total 5 sectors)

(i) probability of getting a green sector $=\frac{Favourable\,\,outcome}{Total\,\,}=\frac{3}{5}$

(ii) probability of getting a Non – Blue sector $=\frac{Favourable\,\,outcome}{Total\,\,}=\frac{3+1}{5}=\frac{4}{5}$

**Q.6. Find the probabilities of the events given in Question 2.**

**Ans: **In throwing a die, possible outcomes of the number appearing on top face = 1, 2, 3, 4, 5, 6

Prime numbers in the outcomes = 2, 3, 5

Non-prime numbers in the outcomes = 1, 4, 6

Numbers greater than 5 = 6

Numbers not greater than 5(including 5) = 1, 2, 3, 4, 5

** **(i) (a) a prime number $=\frac{Favourable\,\,outcome}{Total\,\,}=\frac{3}{6}=\frac{1}{2}$

(b) not a prime number $=\frac{Favourable\,\,outcome}{Total\,\,}=\frac{3}{6}=\frac{1}{2}$

(ii) (a) a number greater than 5 $=\frac{Favourable\,\,outcome}{Total\,\,}=\frac{1}{6}$

(b) a number not greater than 5 $=\frac{Favourable\,\,outcome}{Total\,\,}=\frac{5}{6}$