EduSahara™ Worksheet

Question 1

1.

A coin is tossed 40 times and tail appears 35 times. If the coin is tossed again, what is the probability of getting a head?

(i)

7
8
(ii)

1
4
(iii)

2
9
(iv)

1
8
(v)

0

Question 2

2.

A coin is tossed 90 times and head appears 70 times. If the coin is tossed again, what is the probability of getting a tail?

(i)

1
9
(ii)

3
10
(iii)

7
9
(iv)

2
9
(v)

1
3

Question 3

3.

Two coins are tossed simultaneously 90 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)

2
9
(ii)

13
18
(iii)

6
19
(iv)

1
3
(v)

5
18

Question 4

4.

Two coins are tossed simultaneously 130 times and it was observed that both tails appeared 55 times. If two coins are tossed simultaneously at random, what is the probability of getting both tails?

(i)

11
26
(ii)

15
26
(iii)

6
13
(iv)

4
9
(v)

5
13

Question 5

5.

A die is thrown 60 times. Prime numbers appeared on the upper face 50 times. If a die is thrown at random, what is the probability of getting a prime number?

(i)

5
6
(ii)

6
7
(iii)

1
6
(iv)

2
3
(v)

1

Question 6

6.

A survey of 100 men showed that only 45 of them know French. Out of these men, if one is selected at random, what is the probability that the selected man knows French?

(i)

2
5
(ii)

10
21
(iii)

11
20
(iv)

1
2
(v)

9
20

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

Three-wheeler

Two-wheeler

Four-wheeler

Frequency

25

35

50

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

(i)

4
11
(ii)

5
11
(iii)

6
11
(iv)

1
2

Question 8

8.

The following table shows the blood-groups of 324 students of a class.

Blood group

A

B

AB

O

Number of students

45

81

90

108

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

(i)

1
9
(ii)

6
37
(iii)

1
6
(iv)

31
36
(v)

5
36

Question 9

9.

There are 60 students in a class room of whom 38 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)

19
30
(ii)

11
30
(iii)

3
5
(iv)

20
31
(v)

2
3

Question 10

10.

There are 50 students in a class room of whom 20 are boys and 30 are girls. From these students, one is choosen at random. What is the probability that the choosen student is a girl ?

(i)

3
5
(ii)

4
5
(iii)

2
3
(iv)

2
5

Question 11

11.

In a lottery, there are 23 prizes and 15 blanks. What is the probability of getting a prize?

(i)

11
19
(ii)

15
38
(iii)

8
13
(iv)

23
38
(v)

12
19

Question 12

12.

In a lottery, there are 26 prizes and 16 blanks. What is the probability of not getting a prize?

(i)

3
7
(ii)

1
3
(iii)

8
21
(iv)

9
22
(v)

13
21

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 man starts his vehicle. It starts or it does not starts
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 baby is born. It is a boy or girl

(i)

{b,e}
(ii)

{d,a,c}
(iii)

{b,e,c}
(iv)

{c,e}
(v)

{a,c}

Question 14

14.

Which of the following are possible values of probability?

a)

0.6

b)

-4.4

c)

5

d)

6

7

e)

7

3

(i)

{c,d}
(ii)

{b,a}
(iii)

{e,b,a}
(iv)

{a,d}
(v)

{c,d,a}

Question 15

15.

If P(E) =
0.14
, find P(
E
)

(i)

2.86
(ii)

0.86
(iii)

8.86
(iv)

1.86
(v)

7.86

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 a sure event is 1
d)	The probability of an impossible event is 1
e)	The probability of an imposible event can be > 1

(i)

{d,c,a}
(ii)

{b,a}
(iii)

{a,c}
(iv)

{e,b,a}
(v)

{d,c}

Question 17

17.

Which of the following are true?

a)

P(E) + P(
E
) = 0

b)

P(E) - P(
E
) = 0

c)

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

d)

P(E) = 1 - P(
E
)

e)

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

(i)

{b,e,d}
(ii)

{a,d}
(iii)

{c,a,d}
(iv)

{b,e}
(v)

{d,e}

Question 18

18.

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

(i)

33
50
(ii)

33
100
(iii)

67
100
(iv)

68
101
(v)

17
25

Question 19

19.

A die is thrown 440 times. The number 6 appears on the upper face 72 times. Now the die is thrown at random. What is the probability of getting a 6 ?

(i)

46
55
(ii)

2
11
(iii)

5
28
(iv)

9
55
(v)

8
55

Question 20

20.

171 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

54

72

Compute the probability of the family, chosen at random, having 2 girls.

(i)

11
19
(ii)

7
19
(iii)

9
19
(iv)

8
19
(v)

9
20

Question 21

21.

Three coins are tossed simultaneously 130 times with the following frequencies of different outcomes :

Outcome

3 heads

2 heads

1 heads

No heads

Frequency

25

30

35

40

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

(i)

2
13
(ii)

3
13
(iii)

2
9
(iv)

5
26
(v)

21
26

Question 22

22.

A die is thrown 490 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

50

60

85

90

100

105

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

(i)

1
5
(ii)

9
49
(iii)

10
49
(iv)

40
49
(v)

8
49

Question 23

23.

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

4

29

20

4

20

16

19

19

6

20

23

22

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

(i)

1
2
(ii)

3
4
(iii)

5
6
(iv)

2
3
(v)

4
5

Question 24

24.

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

19

11

17

26

17

23

29

4

4

2

20

27

25

28

What is the empirical probability that an engineer lives greater than 17 km from her place of work?

(i)

4
7
(ii)

5
8
(iii)

3
7
(iv)

5
7

Assignment Key