EduSahara™ Worksheet

Question 1

1.

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

(i)

1
2
(ii)

1
4
(iii)

2
5
(iv)

0
(v)

3
4

Question 2

2.

A coin is tossed 100 times and head appears 40 times. If the coin is tossed again, what is the probability of getting a tail?

(i)

3
5
(ii)

4
5
(iii)

2
5
(iv)

2
3

Question 3

3.

Two coins are tossed simultaneously 40 times and it was observed that both heads appeared 30 times. If two coins are tossed simultaneously at random, what is the probability of getting both heads?

(i)

4
5
(ii)

1
2
(iii)

1
(iv)

3
4
(v)

1
4

Question 4

4.

Two coins are tossed simultaneously 90 times and it was observed that both tails appeared 25 times. If two coins are tossed simultaneously at random, what is the probability of getting both tails?

(i)

1
3
(ii)

13
18
(iii)

2
9
(iv)

6
19
(v)

5
18

Question 5

5.

A die is thrown 70 times. Prime numbers appeared on the upper face 60 times. If a die is thrown at random, what is the probability of getting a prime number?

(i)

7
8
(ii)

5
7
(iii)

1
7
(iv)

6
7
(v)

1

Question 6

6.

A survey of 40 men showed that only 25 of them know Hindi. Out of these men, if one is selected at random, what is the probability that the selected man knows Hindi?

(i)

5
8
(ii)

3
4
(iii)

1
2
(iv)

2
3
(v)

3
8

Question 7

7.

On a particular day, at a crossing in a city, the various types of 150 vehicles going past during a time-interval were observed as under:

Type of Vehicle

Two-wheeler

Three-wheeler

Four-wheeler

Frequency

45

50

55

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

(i)

0
(ii)

1
3
(iii)

2
3
(iv)

1
2

Question 8

8.

The following table shows the blood-groups of 252 students of a class.

Blood group

O

B

A

AB

Number of students

45

54

63

90

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

(i)

6
29
(ii)

3
14
(iii)

1
7
(iv)

5
28
(v)

23
28

Question 9

9.

There are 60 students in a class room of whom 40 are boys and 20 are girls. From these students, one is choosen at random. What is the probability that the choosen student is a boy ?

(i)

1
3
(ii)

1
(iii)

2
3
(iv)

3
4

Question 10

10.

There are 64 students in a class room of whom 30 are boys and 34 are girls. From these students, one is choosen at random. What is the probability that the choosen student is a girl ?

(i)

17
32
(ii)

1
2
(iii)

6
11
(iv)

15
32
(v)

9
16

Question 11

11.

In a lottery, there are 24 prizes and 13 blanks. What is the probability of getting a prize?

(i)

25
38
(ii)

25
37
(iii)

23
37
(iv)

24
37
(v)

13
37

Question 12

12.

In a lottery, there are 26 prizes and 15 blanks. What is the probability of not getting a prize?

(i)

16
41
(ii)

8
21
(iii)

15
41
(iv)

14
41
(v)

26
41

Question 13

13.

Which of the following experiments have equally likely outcomes?

a)	A true/false question is attempted. The answer is either right or wrong
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 man throws a die. The number on the top is either 6 or not 6

(i)

{b,a}
(ii)

{c,d}
(iii)

{e,b,a}
(iv)

{c,d,a}
(v)

{a,d}

Question 14

14.

Which of the following are possible values of probability?

a)

0.4

b)

6

7

c)

3

1

d)

-1.4

e)

5

(i)

{a,b}
(ii)

{d,b}
(iii)

{c,a}
(iv)

{e,c,a}
(v)

{d,b,a}

Question 15

15.

If P(E) =
0.88
, find P(
E
)

(i)

1.12
(ii)

8.12
(iii)

0.12
(iv)

2.12
(v)

7.12

Question 16

16.

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)	For an event E, we have 0 ≤ P(E) ≤ 1
e)	The probability of an unsure event is 0

(i)

{b,d}
(ii)

{a,c}
(iii)

{e,a,c}
(iv)

{c,d}
(v)

{b,d,c}

Question 17

17.

Which of the following are true?

a)

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

b)

P(E) - P(
E
) = 0

c)

P(E) = 1 - P(
E
)

d)

P(E) + P(
E
) = 0

e)

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

(i)

{b,a}
(ii)

{e,b,a}
(iii)

{a,c}
(iv)

{d,c}
(v)

{d,c,a}

Question 18

18.

Two players Sarojini and Keerthi play a tennis match. It is known that the probability of Sarojini winning the match is 0.50. What is the probability of Keerthi winning the match?

(i)

4
5
(ii)

2
3
(iii)

1
2
(iv)

5
6
(v)

3
4

Question 19

19.

A die is thrown 510 times. The number 2 appears on the upper face 98 times. Now the die is thrown at random. What is the probability of getting a 2 ?

(i)

25
128
(ii)

206
255
(iii)

49
255
(iv)

10
51
(v)

16
85

Question 20

20.

198 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

81

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

(i)

5
11
(ii)

3
11
(iii)

5
12
(iv)

4
11
(v)

7
11

Question 21

21.

Three coins are tossed simultaneously 275 times with the following frequencies of different outcomes :

Outcome

3 heads

2 heads

1 heads

No heads

Frequency

50

65

75

85

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

(i)

8
11
(ii)

4
11
(iii)

2
11
(iv)

3
11
(v)

1
3

Question 22

22.

A die is thrown 365 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

35

45

50

60

75

100

If the die is thrown again randomly, find the probability of getting 6 as outcome.

(i)

21
74
(ii)

20
73
(iii)

21
73
(iv)

53
73
(v)

19
73

Question 23

23.

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

20

18

15

26

9

24

26

20

3

23

2

9

30

What is the empirical probability that an engineer lives less than 20 km from her place of work?

(i)

6
13
(ii)

5
13
(iii)

1
2
(iv)

7
13

Question 24

24.

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

5

30

10

30

25

26

8

21

5

24

19

15

25

19

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

(i)

11
14
(ii)

4
15
(iii)

1
7
(iv)

2
7
(v)

3
14

Assignment Key