EduSahara™ Worksheet

Question 1

1.

A coin is tossed 90 times and tail appears 40 times. If the coin is tossed again, what is the probability of getting a head?

(i)

3
5
(ii)

4
9
(iii)

5
9
(iv)

2
3

Question 2

2.

A coin is tossed 80 times and head appears 20 times. If the coin is tossed again, what is the probability of getting a tail?

(i)

1
(ii)

3
4
(iii)

1
2
(iv)

1
4
(v)

4
5

Question 3

3.

Two coins are tossed simultaneously 90 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)

0
(ii)

1
2
(iii)

2
3
(iv)

1
3

Question 4

4.

Two coins are tossed simultaneously 140 times and it was observed that both tails appeared 125 times. If two coins are tossed simultaneously at random, what is the probability of getting both tails?

(i)

25
28
(ii)

6
7
(iii)

3
28
(iv)

13
14
(v)

26
29

Question 5

5.

A die is thrown 60 times. Prime numbers appeared on the upper face 20 times. If a die is thrown at random, what is the probability of getting a prime number?

(i)

2
3
(ii)

0
(iii)

1
3
(iv)

1
2

Question 6

6.

A survey of 100 men showed that only 90 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)

1
10
(ii)

9
10
(iii)

1
(iv)

10
11
(v)

4
5

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

Three-wheeler

Four-wheeler

Frequency

45

65

70

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

(i)

1
2
(ii)

0
(iii)

3
4
(iv)

1
4
(v)

2
5

Question 8

8.

The following table shows the blood-groups of 315 students of a class.

Blood group

B

O

A

AB

Number of students

63

72

81

99

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

(i)

1
5
(ii)

1
3
(iii)

4
5
(iv)

2
5
(v)

0

Question 9

9.

There are 60 students in a class room of whom 34 are boys and 26 are girls. From these students, one is choosen at random. What is the probability that the choosen student is a boy ?

(i)

17
30
(ii)

13
30
(iii)

18
31
(iv)

3
5
(v)

8
15

Question 10

10.

There are 62 students in a class room of whom 28 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)

18
31
(ii)

16
31
(iii)

9
16
(iv)

17
31
(v)

14
31

Question 11

11.

In a lottery, there are 12 prizes and 17 blanks. What is the probability of getting a prize?

(i)

13
29
(ii)

11
29
(iii)

17
29
(iv)

13
30
(v)

12
29

Question 12

12.

In a lottery, there are 30 prizes and 12 blanks. What is the probability of not getting a prize?

(i)

5
7
(ii)

2
7
(iii)

3
7
(iv)

3
8
(v)

1
7

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 6 or not 6
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,b}
(iii)

{d,c}
(iv)

{a,b}
(v)

{b,c}

Question 14

14.

Which of the following are possible values of probability?

a)

5

3

b)

5

c)

1

5

d)

-1

e)

0.5

(i)

{b,e}
(ii)

{d,a,c}
(iii)

{a,c}
(iv)

{b,e,c}
(v)

{c,e}

Question 15

15.

If P(E) =
0.6
, find P(
E
)

(i)

0.4
(ii)

2.4
(iii)

7.4
(iv)

8.4
(v)

1.4

Question 16

16.

Which of the following are true?

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

(i)

{a,e}
(ii)

{c,e,a}
(iii)

{d,b,a}
(iv)

{b,a}
(v)

{c,e}

Question 17

17.

Which of the following are true?

a)

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

b)

P(E) = 1 - P(
E
)

c)

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

d)

P(E) + P(
E
) = 0

e)

P(E) - P(
E
) = 0

(i)

{d,b,a}
(ii)

{c,a}
(iii)

{e,c,a}
(iv)

{d,b}
(v)

{a,b}

Question 18

18.

Two players Rajini and Reshma play a tennis match. It is known that the probability of Rajini winning the match is 0.60. What is the probability of Reshma winning the match?

(i)

1
2
(ii)

1
5
(iii)

2
5
(iv)

3
5

Question 19

19.

A die is thrown 450 times. The number 6 appears on the upper face 76 times. Now the die is thrown at random. What is the probability of getting a 6 ?

(i)

187
225
(ii)

38
225
(iii)

37
225
(iv)

13
75
(v)

39
226

Question 20

20.

225 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

117

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

(i)

18
25
(ii)

8
25
(iii)

6
25
(iv)

4
13
(v)

7
25

Question 21

21.

Three coins are tossed simultaneously 190 times with the following frequencies of different outcomes :

Outcome

3 heads

2 heads

1 heads

No heads

Frequency

30

40

55

65

If the three coins are simultaneously tossed again, compute the probability of '2 heads' coming up.

(i)

4
19
(ii)

5
19
(iii)

15
19
(iv)

1
4
(v)

3
19

Question 22

22.

A die is thrown 410 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

65

70

90

100

If the die is thrown again randomly, find the probability of getting 2 as outcome.

(i)

6
41
(ii)

71
82
(iii)

5
41
(iv)

12
83
(v)

11
82

Question 23

23.

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

2

16

5

1

25

23

15

15

18

What is the empirical probability that an engineer lives less than 16 km from her place of work?

(i)

5
9
(ii)

4
9
(iii)

3
5
(iv)

2
3

Question 24

24.

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

28

9

19

19

17

7

4

1

24

20

27

14

What is the empirical probability that an engineer lives greater than 19 km from her place of work?

(i)

1
2
(ii)

0
(iii)

2
3
(iv)

1
3

Assignment Key