RS Aggarwal solution class 8 chapter 25 Probability Exercise 25B

Exercise 25B

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Q1 | Ex-25B | Class 8 | RS AGGARWAL | chapter 25 | Probability

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Question 1:

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In a spinning wheel, there are 3 white and 5 green sectors. It is spinned. What is the probability of getting a green sector?
(a) $\frac{5}{3}$
(b) $\frac{5}{8}$
(c) $\frac{1}{5}$
(d) $\frac{3}{8}$

Answer 1:

(b) $\frac{5}{8}$

The wheel has a total of  sectors.
Number of green sectors = 5
Now,

Q2 | Ex-25B | Class 8 | RS AGGARWAL | chapter 25 | Probability

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Question 2:

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8 cards are numbered as 1, 2, 3, 4, 5, 6, 7, 8 respectively. They are kept in a box and mixed thoroughly. One card is chosen at random. What is the probability of getting a number less than 4?
(a) $\frac{1}{2}$
(b) $\frac{3}{4}$
(c) $\frac{3}{8}$
(d) $\frac{3}{5}$

Answer 2:

(c) $\frac{3}{8}$

Total number of cards 
Number of cards with numbers less than 4  (cards with numbers 1, 2 and 3)
Now,

Q3 | Ex-25B | Class 8 | RS AGGARWAL | chapter 25 | Probability

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Question 3:

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Two coins are tossed simultaneously. What is the probability of getting one head and one tail?
(a) $\frac{1}{4}$
(b) $\frac{1}{2}$
(c) $\frac{3}{4}$
(d) $\frac{2}{3}$

Answer 3:

(b) $\frac{1}{2}$

When two coins are tossed, the possible outcomes are HH, HT, TH and TT.
​Total number of outcomes $=4$
Number of outcomes with one head and one tail $=2$

Q4 | Ex-25B | Class 8 | RS AGGARWAL | chapter 25 | Probability

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Question 4:

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A bag contains 3 white and 2 red balls. One ball is drawn at random. What is the probability that the ball drawn is red?
(a) $\frac{1}{2}$
(b) $\frac{2}{3}$
(c) $\frac{1}{5}$
(d) $\frac{2}{5}$

Answer 4:

(d) $\frac{2}{5}$

Total number of outcomes $=5$
Number of red balls $=2$

Q5 | Ex-25B | Class 8 | RS AGGARWAL | chapter 25 | Probability

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Question 5:

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A die is thrown. What is the probability of getting 6?
(a) 1
(b) $\frac{1}{6}$
(c) $\frac{6}{1}$
(d) none of these

Answer 5:

(b) $\frac{1}{6}$

The possible outcomes are 1, 2, 3, 4, 5 and 6.
Total number of outcomes
Now,

Q6 | Ex-25B | Class 8 | RS AGGARWAL | chapter 25 | Probability

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Question 6:

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A die is thrown. What is the probability of getting an even number?
(a) $\frac{1}{2}$
(b) $\frac{2}{3}$
(c) $\frac{5}{6}$
(d) $\frac{1}{6}$

Answer 6:

(a) $\frac{1}{2}$

Total number of outcomes  (Numbers: 1, 2, 3, 4, 5 and 6)
The even numbers are 2, 4, and 6.
Number of favourable outcomes 
Now,

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Q7 | Ex-25B | Class 8 | RS AGGARWAL | chapter 25 | Probability

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Question 7:

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From a well-shuffled deck of 52 cards, one card is drawn at random. What is the probability that the drawn card is a queen?
(a) $\frac{1}{4}$
(b) $\frac{1}{52}$
(c) $\frac{1}{13}$
(d) $\frac{1}{26}$

Answer 7:

(c) 

Total number of cards $=52$
Number of queens = 4 (i.e., queen of hearts, queen of diamonds, queen of cloves and queen of spades)

Q8 | Ex-25B | Class 8 | RS AGGARWAL | chapter 25 | Probability

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Question 8:

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From a well-shuffled deck of 52 cards, one card is drawn at random. What is the probability that the drawn card is a black 6?
(a) $\frac{3}{26}$
(b) $\frac{1}{26}$
(c) $\frac{1}{13}$
(d) $\frac{1}{52}$

Answer 8:

(b) 

Total number of cards = 52
Total number of black 6 cards = 2   (6 of spades, 6 of cloves)
Now,