Selina Textbook Solutions: Probability | Mathematics Class 8 ICSE PDF Download

 Page 1


23. Probability 
EXERCISE 23 
Question 1. 
A die is thrown, find the probability of getting: 
(i) a prime number 
(ii) a number greater than 4 
(iii) a number not greater than 4. 
Solution: 
A die has six numbers : 1, 2, 3, 4, 5, 6 
? Number of possible outcomes = 6 
 
Page 2


23. Probability 
EXERCISE 23 
Question 1. 
A die is thrown, find the probability of getting: 
(i) a prime number 
(ii) a number greater than 4 
(iii) a number not greater than 4. 
Solution: 
A die has six numbers : 1, 2, 3, 4, 5, 6 
? Number of possible outcomes = 6 
 
Question 2. 
A coin is tossed. What is the probability of getting: 
(i) a tail? (ii) ahead? 
Solution: 
On tossing a coin once, 
Number of possible outcome = 2 
 
Question 3. 
A coin is tossed twice. Find the probability of getting: 
(i) exactly one head (ii) exactly one tail 
(iii) two tails (iv) two heads 
Solution: 
 
Page 3


23. Probability 
EXERCISE 23 
Question 1. 
A die is thrown, find the probability of getting: 
(i) a prime number 
(ii) a number greater than 4 
(iii) a number not greater than 4. 
Solution: 
A die has six numbers : 1, 2, 3, 4, 5, 6 
? Number of possible outcomes = 6 
 
Question 2. 
A coin is tossed. What is the probability of getting: 
(i) a tail? (ii) ahead? 
Solution: 
On tossing a coin once, 
Number of possible outcome = 2 
 
Question 3. 
A coin is tossed twice. Find the probability of getting: 
(i) exactly one head (ii) exactly one tail 
(iii) two tails (iv) two heads 
Solution: 
 
 
Question 4. 
A letter is chosen from the word ‘PENCIL’ what is the probability that the letter chosen is 
a consonant? 
Solution: 
Total no. of letters in the word ‘PENCIL = 6 
Total Number of Consonant = ‘PNCL’ i.e. 4 
 
Page 4


23. Probability 
EXERCISE 23 
Question 1. 
A die is thrown, find the probability of getting: 
(i) a prime number 
(ii) a number greater than 4 
(iii) a number not greater than 4. 
Solution: 
A die has six numbers : 1, 2, 3, 4, 5, 6 
? Number of possible outcomes = 6 
 
Question 2. 
A coin is tossed. What is the probability of getting: 
(i) a tail? (ii) ahead? 
Solution: 
On tossing a coin once, 
Number of possible outcome = 2 
 
Question 3. 
A coin is tossed twice. Find the probability of getting: 
(i) exactly one head (ii) exactly one tail 
(iii) two tails (iv) two heads 
Solution: 
 
 
Question 4. 
A letter is chosen from the word ‘PENCIL’ what is the probability that the letter chosen is 
a consonant? 
Solution: 
Total no. of letters in the word ‘PENCIL = 6 
Total Number of Consonant = ‘PNCL’ i.e. 4 
 
Question 5. 
A bag contains a black ball, a red ball and a green ball, all the balls are identical in 
shape and size. A ball is drawn from the bag without looking into it. What is the 
probability that the ball drawn is: 
(i) a red ball 
(ii) not a red ball 
(iii) a white ball. 
Solution: 
Total number of possible outcomes = 3 
 
Question 6. 
6. In a single throw of a die, find the probability of getting a number 
(i) greater than 2 
(ii) less than or equal to 2 
(iii) not greater than 2. 
Solution: 
A die has six numbers = 1, 2, 3, 4, 5, 6 
 
Page 5


23. Probability 
EXERCISE 23 
Question 1. 
A die is thrown, find the probability of getting: 
(i) a prime number 
(ii) a number greater than 4 
(iii) a number not greater than 4. 
Solution: 
A die has six numbers : 1, 2, 3, 4, 5, 6 
? Number of possible outcomes = 6 
 
Question 2. 
A coin is tossed. What is the probability of getting: 
(i) a tail? (ii) ahead? 
Solution: 
On tossing a coin once, 
Number of possible outcome = 2 
 
Question 3. 
A coin is tossed twice. Find the probability of getting: 
(i) exactly one head (ii) exactly one tail 
(iii) two tails (iv) two heads 
Solution: 
 
 
Question 4. 
A letter is chosen from the word ‘PENCIL’ what is the probability that the letter chosen is 
a consonant? 
Solution: 
Total no. of letters in the word ‘PENCIL = 6 
Total Number of Consonant = ‘PNCL’ i.e. 4 
 
Question 5. 
A bag contains a black ball, a red ball and a green ball, all the balls are identical in 
shape and size. A ball is drawn from the bag without looking into it. What is the 
probability that the ball drawn is: 
(i) a red ball 
(ii) not a red ball 
(iii) a white ball. 
Solution: 
Total number of possible outcomes = 3 
 
Question 6. 
6. In a single throw of a die, find the probability of getting a number 
(i) greater than 2 
(ii) less than or equal to 2 
(iii) not greater than 2. 
Solution: 
A die has six numbers = 1, 2, 3, 4, 5, 6 
 
? Number of possible outcomes = 6 
 
Question 7. 
A bag contains 3 white, 5 black and 2 red balls, all of the same shape and size. 
A ball is drawn from the bag without looking into it, find the probability that the ball 
drawn is: 
(i) a black ball. 
(ii) a red ball. 
(iii) a white ball. 
(iv) not a red ball. 
(v) not a black ball. 
Solution: 
In a bag, 3 balls are white 
2 balls are red 
5 balls are black 
Total number of balls = 3 + 2 + 5 = 10