EduSahara™ Worksheet

Question 1

1.

A coin is tossed 90 times and tail appears 55 times. If the coin is tossed again, what is the probability of getting a head?

(i)

7
18
(ii)

1
3
(iii)

8
19
(iv)

11
18
(v)

4
9

Question 2

2.

A coin is tossed 80 times and head appears 30 times. If the coin is tossed again, what is the probability of getting a tail?

(i)

2
3
(ii)

3
8
(iii)

3
4
(iv)

1
2
(v)

5
8

Question 3

3.

Two coins are tossed simultaneously 80 times and it was observed that both heads appeared 55 times. If two coins are tossed simultaneously at random, what is the probability of getting both heads?

(i)

12
17
(ii)

3
4
(iii)

5
8
(iv)

11
16
(v)

5
16

Question 4

4.

Two coins are tossed simultaneously 70 times and it was observed that both tails appeared 20 times. If two coins are tossed simultaneously at random, what is the probability of getting both tails?

(i)

1
7
(ii)

3
7
(iii)

2
7
(iv)

3
8
(v)

5
7

Question 5

5.

A die is thrown 50 times. Prime numbers appeared on the upper face 35 times. If a die is thrown at random, what is the probability of getting a prime number?

(i)

3
10
(ii)

4
5
(iii)

3
5
(iv)

8
11
(v)

7
10

Question 6

6.

A survey of 90 men showed that only 30 of them know Telugu. Out of these men, if one is selected at random, what is the probability that the selected man knows Telugu?

(i)

0
(ii)

2
3
(iii)

1
3
(iv)

1
2

Question 7

7.

On a particular day, at a crossing in a city, the various types of 100 vehicles going past during a time-interval were observed as under:

Type of Vehicle

Two-wheeler

Four-wheeler

Three-wheeler

Frequency

25

30

45

Out of these vehicles, if one is choosen at random, what is the probability that the choosen vehicle is a 'Three-wheeler' ?

(i)

1
2
(ii)

9
20
(iii)

2
5
(iv)

10
21
(v)

11
20

Question 8

8.

The following table shows the blood-groups of 360 students of a class.

Blood group

O

B

A

AB

Number of students

54

72

108

126

One student of the class is choosen at random. What is the probability that the choosen student has blood group 'AB' ?

(i)

2
5
(ii)

8
21
(iii)

3
10
(iv)

13
20
(v)

7
20

Question 9

9.

A single unbiased coin is tossed. Find the probability of getting a head.

(i)

1
2
(ii)

3
4
(iii)

2
3
(iv)

4
5
(v)

5
6

Question 10

10.

Two unbiased coins are tossed simultaneously. Find the probability of getting exactly one head.

(i)

1
2
(ii)

2
3
(iii)

5
6
(iv)

3
4
(v)

4
5

Question 11

11.

Two unbiased coins are tossed simultaneously. Find the probability of getting at least one head.

(i)

3
4
(ii)

4
5
(iii)

1
4
(iv)

1
(v)

1
2

Question 12

12.

Two unbiased coins are tossed simultaneously. Find the probability of getting at least two heads.

(i)

3
4
(ii)

1
2
(iii)

1
4
(iv)

2
5
(v)

0

Question 13

13.

Two unbiased coins are tossed simultaneously. Find the probability of getting at most one head.

(i)

1
(ii)

3
4
(iii)

4
5
(iv)

1
4
(v)

1
2

Question 14

14.

Two unbiased coins are tossed simultaneously. Find the probability of getting no head.

(i)

2
5
(ii)

3
4
(iii)

1
2
(iv)

1
4
(v)

0

Question 15

15.

Three unbiased coins are tossed simultaneously. Find the probability of getting exactly one head.

(i)

1
2
(ii)

3
8
(iii)

1
4
(iv)

5
8
(v)

4
9

Question 16

16.

Three unbiased coins are tossed simultaneously. Find the probability of getting at least one head.

(i)

3
4
(ii)

7
8
(iii)

8
9
(iv)

1
8
(v)

1

Question 17

17.

Three unbiased coins are tossed simultaneously. Find the probability of getting at least two heads.

(i)

5
6
(ii)

4
5
(iii)

1
2
(iv)

2
3
(v)

3
4

Question 18

18.

Three unbiased coins are tossed simultaneously. Find the probability of getting at most one head.

(i)

4
5
(ii)

1
2
(iii)

5
6
(iv)

3
4
(v)

2
3

Question 19

19.

Three unbiased coins are tossed simultaneously. Find the probability of getting no head.

(i)

2
9
(ii)

0
(iii)

1
8
(iv)

7
8
(v)

1
4

Question 20

20.

What is the probability of a sure event?

(i)

3
4
(ii)

1
(iii)

1
2
(iv)

1
4
(v)

0

Question 21

21.

What is the probability of an impossible event?

(i)

3
4
(ii)

0
(iii)

1
4
(iv)

1
(v)

1
2

Question 22

22.

There are 70 students in a class room of whom 30 are boys and 40 are girls. From these students, one is choosen at random. What is the probability that the choosen student is a boy ?

(i)

4
7
(ii)

2
7
(iii)

1
2
(iv)

3
7

Question 23

23.

There are 62 students in a class room of whom 26 are boys and 36 are girls. From these students, one is choosen at random. What is the probability that the choosen student is a girl ?

(i)

13
31
(ii)

17
31
(iii)

18
31
(iv)

19
32
(v)

19
31

Question 24

24.

Which of the following are true?

a)	If the probability of failing the exam is 0.2, the probability of passing the exam is 0.8
b)	If the probability is too less, it will become negative
c)	The probability of an event that is very likely to happen is 1
d)	Probability of getting 108 marks out of 100 is 1.08
e)	The probability of an event that cannot happen is unknown

(i)

{b,a}
(ii)

{c,a}
(iii)

{d,e,a}
(iv)

{a}

Question 25

25.

Which of the following experiments have equally likely outcomes?

a)	A man throws a die. The number on the top is either 6 or not 6
b)	A man starts his vehicle. It starts or it does not starts
c)	A ball is hit. It reaches the boundary or not
d)	A baby is born. It is a boy or girl
e)	A true/false question is attempted. The answer is either right or wrong

(i)

{a,d}
(ii)

{b,e}
(iii)

{b,e,d}
(iv)

{c,a,d}
(v)

{d,e}

Question 26

26.

Which of the following are possible values of probability?

a)

4

b)

-2.3

c)

0.2

d)

5

6

e)

5

2

(i)

{e,a,c}
(ii)

{c,d}
(iii)

{b,d,c}
(iv)

{a,c}
(v)

{b,d}

Question 27

27.

If P(E) =
0.17
, find P(
E
)

(i)

0.83
(ii)

7.83
(iii)

2.83
(iv)

8.83
(v)

1.83

Question 28

28.

Which of the following are true?

a)	The probability of an imposible event can be > 1
b)	The probability of an impossible event is 1
c)	The probability of a sure event is 1
d)	The probability of an unsure event is 0
e)	For an event E, we have 0 ≤ P(E) ≤ 1

(i)

{b,e,c}
(ii)

{b,e}
(iii)

{d,a,c}
(iv)

{a,c}
(v)

{c,e}

Question 29

29.

Which of the following are true?

a)

P(E) + P(
E
) = 0

b)

P(E) + P(not E) = 1

c)

P(E) - P(
E
) = 0

d)

P(E) = 1 - P(
E
)

e)

P(E) - P(not E) = 0

(i)

{c,d,b}
(ii)

{c,d}
(iii)

{b,d}
(iv)

{a,b}
(v)

{e,a,b}

Question 30

30.

A die is thrown 400 times. The number 4 appears on the upper face 72 times. Now the die is thrown at random. What is the probability of getting a 4 ?

(i)

4
25
(ii)

41
50
(iii)

10
51
(iv)

1
5
(v)

9
50

Question 31

31.

180 families with 2 children were selected randomly, and the following data were recorded

No. of girls in a family

0

1

2

Number of families

45

63

72

Compute the probability of the family, chosen at random, having 1 girl.

(i)

7
20
(ii)

8
21
(iii)

2
5
(iv)

13
20
(v)

3
10

Question 32

32.

Three coins are tossed simultaneously 215 times with the following frequencies of different outcomes :

Outcome

3 heads

2 heads

1 heads

No heads

Frequency

25

55

65

70

If the three coins are simultaneously tossed again, compute the probability of '1 heads' coming up.

(i)

30
43
(ii)

13
43
(iii)

12
43
(iv)

7
22
(v)

14
43

Question 33

33.

A die is thrown 460 times with the frequencies for outcomes 1, 2, 3, 4, 5 and 6 as given in the following table

Outcome

1

2

3

4

5

6

Frequency

40

60

80

85

95

100

If the die is thrown again randomly, find the probability of getting 5 as outcome.

(i)

5
23
(ii)

19
92
(iii)

9
46
(iv)

73
92
(v)

20
93

Question 34

34.

The distances (in km) of engineers from their residence to their place of work were found as follows

25

28

24

8

1

23

25

22

6

8

15

What is the empirical probability that an engineer lives less than 25 km from her place of work?

(i)

9
11
(ii)

3
4
(iii)

8
11
(iv)

7
11
(v)

3
11

Question 35

35.

The distances (in km) of engineers from their residence to their place of work were found as follows

11

17

12

8

12

26

4

8

9

24

14

29

2

What is the empirical probability that an engineer lives greater than 8 km from her place of work?

(i)

10
13
(ii)

8
13
(iii)

5
7
(iv)

4
13
(v)

9
13

Question 36

36.

Suppose a die is thrown on a rectangular region as shown below. What is the probability that it will land inside the circle of diameter 14.00 cm?

(i)

17
75
(ii)

155
676
(iii)

154
675
(iv)

521
675
(v)

31
135

Assignment Key