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)

2
3
(iii)

5
7
(iv)

4
7
(v)

5
14

Question 2

2.

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

(i)

3
4
(ii)

5
6
(iii)

1
2
(iv)

4
5
(v)

2
3

Question 3

3.

Two coins are tossed simultaneously 60 times and it was observed that both tails appeared 45 times. If two coins are tossed simultaneously at random, what is the probability of getting both tails?

(i)

4
5
(ii)

1
4
(iii)

3
4
(iv)

1
2
(v)

1

Question 4

4.

Three coins are tossed simultaneously 180 times with the following frequencies of different outcomes :

Outcome

3 heads

2 heads

1 heads

No heads

Frequency

30

45

50

55

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

(i)

6
19
(ii)

2
9
(iii)

13
18
(iv)

1
3
(v)

5
18

Question 5

5.

There are 60 students in a class room of whom 36 are boys and 24 are girls. From these students, one is choosen at random. What is the probability that the choosen student is a girl ?

(i)

1
5
(ii)

2
5
(iii)

3
5
(iv)

1
2

Question 6

6.

Which of the following are true?

a)

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

b)

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

c)

P(E) = 1 - P(
E
)

d)

P(E) + P(
E
) = 0

e)

P(E) - P(
E
) = 0

(i)

{d,c}
(ii)

{e,b,a}
(iii)

{a,c}
(iv)

{b,a}
(v)

{d,c,a}

Question 7

7.

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

11

3

19

22

10

29

29

20

12

14

23

22

15

16

9

What is the empirical probability that an engineer lives greater than 10 km from her place of work?

(i)

1
(ii)

5
6
(iii)

3
5
(iv)

1
5
(v)

4
5

Question 8

8.

Two coins are tossed simultaneously 50 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)

2
5
(ii)

4
5
(iii)

3
5
(iv)

2
3

Question 9

9.

There are 42 students in a class room of whom 20 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)

3
7
(ii)

11
21
(iii)

10
21
(iv)

1
2

Question 10

10.

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

45

50

55

60

75

80

If the die is thrown again randomly, find the probability of getting 4 as outcome.

(i)

13
74
(ii)

12
73
(iii)

61
73
(iv)

13
73
(v)

11
73

Question 11

11.

If P(E) =
0.67
, find P(
E
)

(i)

2.33
(ii)

7.33
(iii)

1.33
(iv)

0.33
(v)

8.33

Question 12

12.

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

4

20

2

30

2

23

22

1

What is the empirical probability that an engineer lives less than 4 km from her place of work?

(i)

1
2
(ii)

3
8
(iii)

4
9
(iv)

1
4
(v)

5
8

Question 13

13.

Which of the following are possible values of probability?

a)

3

4

b)

-5.4

c)

0.2

d)

3

e)

7

4

(i)

{d,c,a}
(ii)

{a,c}
(iii)

{e,b,a}
(iv)

{b,a}
(v)

{d,c}

Question 14

14.

On a particular day, at a crossing in a city, the various types of 205 vehicles going past during a time-interval were observed as under:

Type of Vehicle

Three-wheeler

Four-wheeler

Two-wheeler

Frequency

45

75

85

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

(i)

3
7
(ii)

16
41
(iii)

24
41
(iv)

17
41
(v)

18
41

Question 15

15.

A die is thrown 600 times. The number 2 appears on the upper face 92 times. Now the die is thrown at random. What is the probability of getting a 2 ?

(i)

127
150
(ii)

11
75
(iii)

23
150
(iv)

4
25
(v)

24
151

Question 16

16.

A die is thrown 295 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

40

45

50

55

75

If the die is thrown again randomly, find the probability of getting 1 as outcome.

(i)

7
60
(ii)

53
59
(iii)

7
59
(iv)

6
59
(v)

5
59

Question 17

17.

Which of the following experiments have equally likely outcomes?

a)	A man starts his vehicle. It starts or it does not starts
b)	A ball is hit. It reaches the boundary or not
c)	A baby is born. It is a boy or girl
d)	A true/false question is attempted. The answer is either right or wrong
e)	A man throws a die. The number on the top is either 3 or not 3

(i)

{b,d,c}
(ii)

{b,d}
(iii)

{a,c}
(iv)

{e,a,c}
(v)

{c,d}

Question 18

18.

Which of the following are true?

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

(i)

{e,a,b}
(ii)

{b,d}
(iii)

{a,b}
(iv)

{c,d,b}
(v)

{c,d}

Question 19

19.

In a lottery, there are 25 prizes and 16 blanks. What is the probability of not getting a prize?

(i)

17
42
(ii)

17
41
(iii)

25
41
(iv)

16
41
(v)

15
41

Question 20

20.

252 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

72

81

99

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

(i)

10
29
(ii)

9
28
(iii)

5
14
(iv)

19
28
(v)

2
7

Question 21

21.

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)

7
10
(iv)

3
5
(v)

8
11

Question 22

22.

A survey of 90 men showed that only 70 of them know Sanskrit. Out of these men, if one is selected at random, what is the probability that the selected man knows Sanskrit?

(i)

7
9
(ii)

8
9
(iii)

2
9
(iv)

4
5
(v)

2
3

Question 23

23.

The following table shows the blood-groups of 405 students of a class.

Blood group

AB

O

B

A

Number of students

63

90

108

144

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

(i)

29
45
(ii)

16
45
(iii)

1
3
(iv)

17
46
(v)

17
45

Question 24

24.

In a lottery, there are 27 prizes and 13 blanks. What is the probability of getting a prize?

(i)

27
40
(ii)

13
20
(iii)

7
10
(iv)

13
40
(v)

28
41

Question 25

25.

A coin is tossed 60 times and head appears 50 times. If the coin is tossed again, what is the probability of getting a tail?

(i)

1
3
(ii)

2
7
(iii)

0
(iv)

1
6
(v)

5
6

Assignment Key