EduSahara™ Worksheet

Question 1

1.

A coin is tossed 70 times and tail appears 25 times. If the coin is tossed again, what is the probability of getting a head?

(i)

9
14
(ii)

5
14
(iii)

2
3
(iv)

4
7
(v)

5
7

Question 2

2.

A coin is tossed 40 times and head appears 30 times. If the coin is tossed again, what is the probability of getting a tail?

(i)

1
4
(ii)

0
(iii)

3
4
(iv)

1
2
(v)

2
5

Question 3

3.

Two coins are tossed simultaneously 90 times and it was observed that both heads appeared 80 times. If two coins are tossed simultaneously at random, what is the probability of getting both heads?

(i)

8
9
(ii)

1
9
(iii)

9
10
(iv)

7
9
(v)

1

Question 4

4.

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

(i)

5
8
(ii)

5
16
(iii)

11
16
(iv)

12
17
(v)

3
4

Question 5

5.

A die is thrown 140 times. Prime numbers appeared on the upper face 90 times. If a die is thrown at random, what is the probability of getting a prime number?

(i)

5
14
(ii)

2
3
(iii)

5
7
(iv)

4
7
(v)

9
14

Question 6

6.

A survey of 80 men showed that only 35 of them know German. Out of these men, if one is selected at random, what is the probability that the selected man knows German?

(i)

1
2
(ii)

7
16
(iii)

9
16
(iv)

3
8
(v)

8
17

Question 7

7.

On a particular day, at a crossing in a city, the various types of 110 vehicles going past during a time-interval were observed as under:

Type of Vehicle

Two-wheeler

Four-wheeler

Three-wheeler

Frequency

30

35

45

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

(i)

2
11
(ii)

8
11
(iii)

1
3
(iv)

4
11
(v)

3
11

Question 8

8.

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

Blood group

B

O

AB

A

Number of students

45

81

99

135

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

(i)

10
41
(ii)

1
4
(iii)

31
40
(iv)

9
40
(v)

1
5

Question 9

9.

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

(i)

4
5
(ii)

1
2
(iii)

3
4
(iv)

5
6
(v)

2
3

Question 10

10.

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

(i)

4
5
(ii)

5
6
(iii)

3
4
(iv)

2
3
(v)

1
2

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
2
(v)

1

Question 12

12.

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

(i)

1
4
(ii)

0
(iii)

1
2
(iv)

2
5
(v)

3
4

Question 13

13.

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

(i)

1
(ii)

4
5
(iii)

3
4
(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)

0
(iii)

1
2
(iv)

1
4
(v)

3
4

Question 15

15.

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

(i)

1
2
(ii)

4
9
(iii)

3
8
(iv)

1
4
(v)

5
8

Question 16

16.

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

(i)

1
(ii)

1
8
(iii)

7
8
(iv)

8
9
(v)

3
4

Question 17

17.

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

(i)

3
4
(ii)

5
6
(iii)

4
5
(iv)

1
2
(v)

2
3

Question 18

18.

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

(i)

4
5
(ii)

5
6
(iii)

3
4
(iv)

2
3
(v)

1
2

Question 19

19.

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

(i)

1
4
(ii)

7
8
(iii)

2
9
(iv)

0
(v)

1
8

Question 20

20.

What is the probability of a sure event?

(i)

1
2
(ii)

3
4
(iii)

1
(iv)

0
(v)

1
4

Question 21

21.

What is the probability of an impossible event?

(i)

1
4
(ii)

1
(iii)

1
2
(iv)

0
(v)

3
4

Question 22

22.

There are 48 students in a class room of whom 26 are boys and 22 are girls. From these students, one is choosen at random. What is the probability that the choosen student is a boy ?

(i)

11
24
(ii)

14
25
(iii)

13
24
(iv)

7
12
(v)

1
2

Question 23

23.

There are 62 students in a class room of whom 32 are boys and 30 are girls. From these students, one is choosen at random. What is the probability that the choosen student is a girl ?

(i)

14
31
(ii)

15
31
(iii)

1
2
(iv)

16
31

Question 24

24.

Which of the following are true?

a)	The probability of an event that is very likely to happen is 1
b)	If the probability is too less, it will become negative
c)	If the probability of failing the exam is 0.8, the probability of passing the exam is 0.2
d)	The probability of an event that cannot happen is unknown
e)	Probability of getting 102 marks out of 100 is 1.02

(i)

{c}
(ii)

{d,e,c}
(iii)

{a,c}
(iv)

{b,c}

Question 25

25.

Which of the following experiments have equally likely outcomes?

a)	A ball is hit. It reaches the boundary or not
b)	A man throws a die. The number on the top is either 3 or not 3
c)	A man starts his vehicle. It starts or it does not starts
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)

{d,e}
(ii)

{b,e}
(iii)

{a,d}
(iv)

{c,a,d}
(v)

{b,e,d}

Question 26

26.

Which of the following are possible values of probability?

a)

8

1

b)

5

c)

3

9

d)

0.5

e)

-5

(i)

{a,c}
(ii)

{b,d}
(iii)

{b,d,c}
(iv)

{c,d}
(v)

{e,a,c}

Question 27

27.

If P(E) =
0.5
, find P(
E
)

(i)

0.5
(ii)

2.5
(iii)

8.5
(iv)

1.5
(v)

7.5

Question 28

28.

Which of the following are true?

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

(i)

{b,e}
(ii)

{c,e}
(iii)

{d,a,b}
(iv)

{c,e,b}
(v)

{a,b}

Question 29

29.

Which of the following are true?

a)

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

b)

P(E) = 1 - P(
E
)

c)

P(E) - P(
E
) = 0

d)

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

e)

P(E) + P(
E
) = 0

(i)

{e,a,b}
(ii)

{c,d}
(iii)

{b,d}
(iv)

{a,b}
(v)

{c,d,b}

Question 30

30.

A die is thrown 500 times. The number 4 appears on the upper face 100 times. Now the die is thrown at random. What is the probability of getting a 4 ?

(i)

0
(ii)

1
5
(iii)

4
5
(iv)

2
5
(v)

1
3

Question 31

31.

207 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

72

90

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

(i)

9
23
(ii)

7
23
(iii)

15
23
(iv)

8
23
(v)

3
8

Question 32

32.

Three coins are tossed simultaneously 245 times with the following frequencies of different outcomes :

Outcome

3 heads

2 heads

1 heads

No heads

Frequency

25

65

75

80

If the three coins are simultaneously tossed again, compute the probability of 'No heads' coming up.

(i)

17
50
(ii)

33
49
(iii)

16
49
(iv)

15
49
(v)

17
49

Question 33

33.

A die is thrown 450 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

30

55

80

85

90

110

If the die is thrown again randomly, find the probability of getting 3 as outcome.

(i)

8
45
(ii)

7
45
(iii)

37
45
(iv)

1
5
(v)

9
46

Question 34

34.

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

20

5

21

6

22

15

17

26

7

15

What is the empirical probability that an engineer lives less than 17 km from her place of work?

(i)

3
4
(ii)

4
5
(iii)

5
6
(iv)

1
2
(v)

2
3

Question 35

35.

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

3

17

15

3

23

6

26

4

1

24

What is the empirical probability that an engineer lives greater than 23 km from her place of work?

(i)

4
5
(ii)

1
3
(iii)

1
5
(iv)

0
(v)

2
5

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 8.00 cm?

(i)

29
105
(ii)

88
315
(iii)

89
316
(iv)

227
315
(v)

89
315

Assignment Key