Probability - Exercise 25B | Mathematics (Maths) Class 8 PDF Download

 Page 1


 
 
  
     
         
 
 
         
 
        
 
 
Q u e s t i o n : 1 3
Tick
? the correct answer:
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
5
3
b
5
8
c
1
5
d
3
8
S o l u t i o n :
b
 
5
8
The wheel has a total of 5 +3 = 8
 sectors.
Number of green sectors = 5
Now, P
(getting a green sector)
=
5
8
Q u e s t i o n : 1 4
Page 2


 
 
  
     
         
 
 
         
 
        
 
 
Q u e s t i o n : 1 3
Tick
? the correct answer:
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
5
3
b
5
8
c
1
5
d
3
8
S o l u t i o n :
b
 
5
8
The wheel has a total of 5 +3 = 8
 sectors.
Number of green sectors = 5
Now, P
(getting a green sector)
=
5
8
Q u e s t i o n : 1 4
Tick
? the correct answer:
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
1
2
b
3
4
c
3
8
d
3
5
S o l u t i o n :
c
 
3
8
Total number of cards = 8
Number of cards with numbers less than 4 = 3
 cardswithnumbers1, 2and3
Now, P
(getting a number less than 4)
=
3
8
Q u e s t i o n : 1 5
Tick
? the correct answer:
Two coins are tossed simultaneously. What is the probability of getting one head and one tail?
a
1
4
b
1
2
c
3
4
d
2
3
S o l u t i o n :
b
 
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
Page 3


 
 
  
     
         
 
 
         
 
        
 
 
Q u e s t i o n : 1 3
Tick
? the correct answer:
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
5
3
b
5
8
c
1
5
d
3
8
S o l u t i o n :
b
 
5
8
The wheel has a total of 5 +3 = 8
 sectors.
Number of green sectors = 5
Now, P
(getting a green sector)
=
5
8
Q u e s t i o n : 1 4
Tick
? the correct answer:
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
1
2
b
3
4
c
3
8
d
3
5
S o l u t i o n :
c
 
3
8
Total number of cards = 8
Number of cards with numbers less than 4 = 3
 cardswithnumbers1, 2and3
Now, P
(getting a number less than 4)
=
3
8
Q u e s t i o n : 1 5
Tick
? the correct answer:
Two coins are tossed simultaneously. What is the probability of getting one head and one tail?
a
1
4
b
1
2
c
3
4
d
2
3
S o l u t i o n :
b
 
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
Now, P
(one head and one tail)
=
2
4
=
1
2
Q u e s t i o n : 1 6
Tick
? the correct answer:
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
1
2
b
2
3
c
1
5
d
2
5
S o l u t i o n :
d
 
2
5
Total number of outcomes = 5
Number of red balls = 2
Now, P
(red ball)
=
2
5
Q u e s t i o n : 1 7
Tick
? the correct answer:
A die is thrown. What is the probability of getting 6?
a
1
b
1
6
c
6
1
d
none of these
S o l u t i o n :
b
 
1
6
The possible outcomes are 1, 2, 3, 4, 5 and 6.
Total number of outcomes = 6
Page 4


 
 
  
     
         
 
 
         
 
        
 
 
Q u e s t i o n : 1 3
Tick
? the correct answer:
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
5
3
b
5
8
c
1
5
d
3
8
S o l u t i o n :
b
 
5
8
The wheel has a total of 5 +3 = 8
 sectors.
Number of green sectors = 5
Now, P
(getting a green sector)
=
5
8
Q u e s t i o n : 1 4
Tick
? the correct answer:
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
1
2
b
3
4
c
3
8
d
3
5
S o l u t i o n :
c
 
3
8
Total number of cards = 8
Number of cards with numbers less than 4 = 3
 cardswithnumbers1, 2and3
Now, P
(getting a number less than 4)
=
3
8
Q u e s t i o n : 1 5
Tick
? the correct answer:
Two coins are tossed simultaneously. What is the probability of getting one head and one tail?
a
1
4
b
1
2
c
3
4
d
2
3
S o l u t i o n :
b
 
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
Now, P
(one head and one tail)
=
2
4
=
1
2
Q u e s t i o n : 1 6
Tick
? the correct answer:
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
1
2
b
2
3
c
1
5
d
2
5
S o l u t i o n :
d
 
2
5
Total number of outcomes = 5
Number of red balls = 2
Now, P
(red ball)
=
2
5
Q u e s t i o n : 1 7
Tick
? the correct answer:
A die is thrown. What is the probability of getting 6?
a
1
b
1
6
c
6
1
d
none of these
S o l u t i o n :
b
 
1
6
The possible outcomes are 1, 2, 3, 4, 5 and 6.
Total number of outcomes = 6
Now, P
(getting 6)
 = 
1
6
Q u e s t i o n : 1 8
Tick
? the correct answer:
A die is thrown. What is the probability of getting an even number?
a
1
2
b
2
3
c
5
6
d
1
6
S o l u t i o n :
a
 
1
2
Total number of outcomes = 6
 Numbers: 1, 2, 3, 4, 5and6
The even numbers are 2, 4, and 6.
Number of favourable outcomes = 3
Now, P
(even number)
=
3
6
=
1
2
Q u e s t i o n : 1 9
Tick
? the correct answer:
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
1
4
b
1
52
c
1
13
d
1
26
S o l u t i o n :
Page 5


 
 
  
     
         
 
 
         
 
        
 
 
Q u e s t i o n : 1 3
Tick
? the correct answer:
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
5
3
b
5
8
c
1
5
d
3
8
S o l u t i o n :
b
 
5
8
The wheel has a total of 5 +3 = 8
 sectors.
Number of green sectors = 5
Now, P
(getting a green sector)
=
5
8
Q u e s t i o n : 1 4
Tick
? the correct answer:
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
1
2
b
3
4
c
3
8
d
3
5
S o l u t i o n :
c
 
3
8
Total number of cards = 8
Number of cards with numbers less than 4 = 3
 cardswithnumbers1, 2and3
Now, P
(getting a number less than 4)
=
3
8
Q u e s t i o n : 1 5
Tick
? the correct answer:
Two coins are tossed simultaneously. What is the probability of getting one head and one tail?
a
1
4
b
1
2
c
3
4
d
2
3
S o l u t i o n :
b
 
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
Now, P
(one head and one tail)
=
2
4
=
1
2
Q u e s t i o n : 1 6
Tick
? the correct answer:
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
1
2
b
2
3
c
1
5
d
2
5
S o l u t i o n :
d
 
2
5
Total number of outcomes = 5
Number of red balls = 2
Now, P
(red ball)
=
2
5
Q u e s t i o n : 1 7
Tick
? the correct answer:
A die is thrown. What is the probability of getting 6?
a
1
b
1
6
c
6
1
d
none of these
S o l u t i o n :
b
 
1
6
The possible outcomes are 1, 2, 3, 4, 5 and 6.
Total number of outcomes = 6
Now, P
(getting 6)
 = 
1
6
Q u e s t i o n : 1 8
Tick
? the correct answer:
A die is thrown. What is the probability of getting an even number?
a
1
2
b
2
3
c
5
6
d
1
6
S o l u t i o n :
a
 
1
2
Total number of outcomes = 6
 Numbers: 1, 2, 3, 4, 5and6
The even numbers are 2, 4, and 6.
Number of favourable outcomes = 3
Now, P
(even number)
=
3
6
=
1
2
Q u e s t i o n : 1 9
Tick
? the correct answer:
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
1
4
b
1
52
c
1
13
d
1
26
S o l u t i o n :
c
 
1
13
Total number of cards = 52
Number of queens = 4 i. e. , queenofhearts, queenofdiamonds, queenofclovesandqueenofspades
Now, P
(queen)
=
4
52
=
1
13
Q u e s t i o n : 2 0
Tick
? the correct answer:
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
3
26
b
1
26
c
1
13
d
1
52
S o l u t i o n :
b
 
1
26
Total number of cards = 52
Total number of black 6 cards = 2   6ofspades, 6ofcloves
Now, P
(black 6)
=
2
52
=
1
26