EduSahara™ Worksheet

Question 1

1.

A coin is tossed 40 times and tail appears 25 times. If the coin is tossed again, what is the probability of getting a head?

(i)

3
8
(ii)

5
8
(iii)

4
9
(iv)

1
4
(v)

1
2

Question 2

2.

A coin is tossed 40 times and head appears 25 times. If the coin is tossed again, what is the probability of getting a tail?

(i)

5
8
(ii)

3
8
(iii)

1
4
(iv)

4
9
(v)

1
2

Question 3

3.

Two coins are tossed simultaneously 80 times and it was observed that both heads appeared 25 times. If two coins are tossed simultaneously at random, what is the probability of getting both heads?

(i)

5
16
(ii)

1
4
(iii)

3
8
(iv)

6
17
(v)

11
16

Question 4

4.

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)

1
(iv)

3
4
(v)

1
2

Question 5

5.

A die is thrown 60 times. Prime numbers appeared on the upper face 30 times. If a die is thrown at random, what is the probability of getting a prime number?

(i)

3
4
(ii)

5
6
(iii)

4
5
(iv)

1
2
(v)

2
3

Question 6

6.

A survey of 120 men showed that only 40 of them know English. Out of these men, if one is selected at random, what is the probability that the selected man knows English?

(i)

1
3
(ii)

2
3
(iii)

0
(iv)

1
2

Question 7

7.

On a particular day, at a crossing in a city, the various types of 180 vehicles going past during a time-interval were observed as under:

Type of Vehicle

Two-wheeler

Four-wheeler

Three-wheeler

Frequency

40

50

90

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

(i)

5
6
(ii)

2
3
(iii)

1
2
(iv)

4
5
(v)

3
4

Question 8

8.

The following table shows the blood-groups of 432 students of a class.

Blood group

B

A

O

AB

Number of students

63

108

126

135

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

(i)

0
(ii)

1
4
(iii)

2
5
(iv)

3
4
(v)

1
2

Question 9

9.

There are 68 students in a class room of whom 34 are boys and 34 are girls. From these students, one is choosen at random. What is the probability that the choosen student is a boy ?

(i)

3
4
(ii)

5
6
(iii)

1
2
(iv)

2
3
(v)

4
5

Question 10

10.

There are 42 students in a class room of whom 22 are boys and 20 are girls. From these students, one is choosen at random. What is the probability that the choosen student is a girl ?

(i)

11
21
(ii)

1
2
(iii)

3
7
(iv)

10
21

Question 11

11.

In a lottery, there are 20 prizes and 12 blanks. What is the probability of getting a prize?

(i)

5
8
(ii)

3
4
(iii)

2
3
(iv)

1
2
(v)

3
8

Question 12

12.

In a lottery, there are 27 prizes and 12 blanks. What is the probability of not getting a prize?

(i)

5
13
(ii)

4
13
(iii)

9
13
(iv)

5
14
(v)

3
13

Question 13

13.

Which of the following experiments have equally likely outcomes?

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

(i)

{e,a,b}
(ii)

{d,c}
(iii)

{a,b}
(iv)

{b,c}
(v)

{d,c,b}

Question 14

14.

Which of the following are possible values of probability?

a)

0.33

b)

1

8

c)

-4.2

d)

2

e)

3

2

(i)

{c,a}
(ii)

{d,b,a}
(iii)

{a,b}
(iv)

{e,c,a}
(v)

{d,b}

Question 15

15.

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

(i)

2.83
(ii)

1.83
(iii)

8.83
(iv)

0.83
(v)

7.83

Question 16

16.

Which of the following are true?

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

(i)

{b,e}
(ii)

{c,a,d}
(iii)

{a,d}
(iv)

{d,e}
(v)

{b,e,d}

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) - P(not E) = 0

d)

P(E) + P(
E
) = 0

e)

P(E) = 1 - P(
E
)

(i)

{c,e,a}
(ii)

{c,e}
(iii)

{d,b,a}
(iv)

{b,a}
(v)

{a,e}

Question 18

18.

Two players Seema and Swetha play a tennis match. It is known that the probability of Seema winning the match is 0.33. What is the probability of Swetha winning the match?

(i)

33
50
(ii)

67
100
(iii)

17
25
(iv)

33
100
(v)

68
101

Question 19

19.

A die is thrown 490 times. The number 3 appears on the upper face 74 times. Now the die is thrown at random. What is the probability of getting a 3 ?

(i)

36
245
(ii)

38
245
(iii)

208
245
(iv)

37
245
(v)

19
123

Question 20

20.

234 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

90

99

Compute the probability of the family, chosen at random, having no girls.

(i)

2
13
(ii)

3
13
(iii)

2
9
(iv)

5
26
(v)

21
26

Question 21

21.

Three coins are tossed simultaneously 150 times with the following frequencies of different outcomes :

Outcome

3 heads

2 heads

1 heads

No heads

Frequency

25

30

40

55

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

(i)

4
15
(ii)

5
16
(iii)

1
5
(iv)

1
3
(v)

11
15

Question 22

22.

A die is thrown 360 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

25

35

50

70

80

100

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

(i)

1
3
(ii)

13
18
(iii)

2
9
(iv)

5
18
(v)

6
19

Question 23

23.

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

11

28

8

5

21

26

30

21

5

18

10

What is the empirical probability that an engineer lives less than 11 km from her place of work?

(i)

5
12
(ii)

5
11
(iii)

3
11
(iv)

4
11
(v)

7
11

Question 24

24.

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

24

18

2

20

4

27

18

10

24

28

19

28

What is the empirical probability that an engineer lives greater than 24 km from her place of work?

(i)

2
5
(ii)

3
4
(iii)

1
2
(iv)

1
4
(v)

0

Assignment Key