EduSahara™ Worksheet

Question 1

1.

A coin is tossed 50 times and tail appears 20 times. If the coin is tossed again, what is the probability of getting a head?

(i)

2
3
(ii)

2
5
(iii)

3
5
(iv)

4
5

Question 2

2.

A coin is tossed 60 times and head appears 20 times. If the coin is tossed again, what is the probability of getting a tail?

(i)

2
3
(ii)

3
4
(iii)

1
(iv)

1
3

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)

1
4
(ii)

6
17
(iii)

5
16
(iv)

3
8
(v)

11
16

Question 4

4.

Two coins are tossed simultaneously 110 times and it was observed that both tails appeared 35 times. If two coins are tossed simultaneously at random, what is the probability of getting both tails?

(i)

4
11
(ii)

15
22
(iii)

8
23
(iv)

3
11
(v)

7
22

Question 5

5.

A die is thrown 150 times. Prime numbers appeared on the upper face 85 times. If a die is thrown at random, what is the probability of getting a prime number?

(i)

18
31
(ii)

8
15
(iii)

3
5
(iv)

17
30
(v)

13
30

Question 6

6.

A survey of 90 men showed that only 35 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)

7
18
(iii)

11
18
(iv)

4
9
(v)

8
19

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

Four-wheeler

Two-wheeler

Three-wheeler

Frequency

25

30

55

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

(i)

3
4
(ii)

2
3
(iii)

4
5
(iv)

5
6
(v)

1
2

Question 8

8.

The following table shows the blood-groups of 342 students of a class.

Blood group

AB

O

A

B

Number of students

45

54

108

135

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

(i)

7
19
(ii)

16
39
(iii)

15
38
(iv)

8
19
(v)

23
38

Question 9

9.

There are 54 students in a class room of whom 26 are boys and 28 are girls. From these students, one is choosen at random. What is the probability that the choosen student is a boy ?

(i)

13
27
(ii)

1
2
(iii)

14
27
(iv)

4
9

Question 10

10.

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 girl ?

(i)

5
12
(ii)

1
2
(iii)

13
24
(iv)

11
24
(v)

12
25

Question 11

11.

In a lottery, there are 11 prizes and 18 blanks. What is the probability of getting a prize?

(i)

2
5
(ii)

11
29
(iii)

18
29
(iv)

12
29
(v)

10
29

Question 12

12.

In a lottery, there are 22 prizes and 13 blanks. What is the probability of not getting a prize?

(i)

7
18
(ii)

2
5
(iii)

13
35
(iv)

12
35
(v)

22
35

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 baby is born. It is a boy or girl
c)	A man throws a die. The number on the top is either 4 or not 4
d)	A man starts his vehicle. It starts or it does not starts
e)	A ball is hit. It reaches the boundary or not

(i)

{c,a}
(ii)

{e,c,a}
(iii)

{a,b}
(iv)

{d,b}
(v)

{d,b,a}

Question 14

14.

Which of the following are possible values of probability?

a)

-5.1

b)

1

2

c)

2

d)

9

5

e)

0.33

(i)

{c,e,b}
(ii)

{b,e}
(iii)

{a,b}
(iv)

{c,e}
(v)

{d,a,b}

Question 15

15.

If P(E) =
0.11
, find P(
E
)

(i)

0.89
(ii)

1.89
(iii)

2.89
(iv)

7.89
(v)

8.89

Question 16

16.

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

(i)

{b,c}
(ii)

{d,c}
(iii)

{d,c,b}
(iv)

{a,b}
(v)

{e,a,b}

Question 17

17.

Which of the following are true?

a)

P(E) = 1 - P(
E
)

b)

P(E) + P(
E
) = 0

c)

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

d)

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

e)

P(E) - P(
E
) = 0

(i)

{b,a}
(ii)

{d,c}
(iii)

{d,c,a}
(iv)

{e,b,a}
(v)

{a,c}

Question 18

18.

Two players Sangeeta and Jasmine play a tennis match. It is known that the probability of Sangeeta winning the match is 0.38. What is the probability of Jasmine winning the match?

(i)

19
50
(ii)

31
50
(iii)

3
5
(iv)

32
51
(v)

16
25

Question 19

19.

A die is thrown 370 times. The number 3 appears on the upper face 70 times. Now the die is thrown at random. What is the probability of getting a 3 ?

(i)

30
37
(ii)

4
19
(iii)

7
37
(iv)

8
37
(v)

6
37

Question 20

20.

261 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

54

99

108

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

(i)

2
5
(ii)

18
29
(iii)

10
29
(iv)

12
29
(v)

11
29

Question 21

21.

Three coins are tossed simultaneously 205 times with the following frequencies of different outcomes :

Outcome

3 heads

2 heads

1 heads

No heads

Frequency

25

30

65

85

If the three coins are simultaneously tossed again, compute the probability of '3 heads' coming up.

(i)

6
41
(ii)

4
41
(iii)

36
41
(iv)

1
7
(v)

5
41

Question 22

22.

A die is thrown 335 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

75

80

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

(i)

57
67
(ii)

11
67
(iii)

9
67
(iv)

10
67
(v)

11
68

Question 23

23.

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

24

28

5

17

4

3

7

9

25

17

14

9

18

25

What is the empirical probability that an engineer lives less than 9 km from her place of work?

(i)

2
7
(ii)

5
7
(iii)

3
7
(iv)

1
7
(v)

3
8

Question 24

24.

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

18

29

9

4

16

21

15

29

3

3

7

What is the empirical probability that an engineer lives greater than 15 km from her place of work?

(i)

6
11
(ii)

5
11
(iii)

4
11
(iv)

1
2

Assignment Key