EduSahara™ Worksheet

Question 1

1.

A coin is tossed 80 times and tail appears 35 times. If the coin is tossed again, what is the probability of getting a head?

(i)

10
17
(ii)

7
16
(iii)

1
2
(iv)

5
8
(v)

9
16

Question 2

2.

A coin is tossed 40 times and head appears 20 times. If the coin is tossed again, what is the probability of getting a tail?

(i)

5
6
(ii)

2
3
(iii)

1
2
(iv)

4
5
(v)

3
4

Question 3

3.

Two coins are tossed simultaneously 150 times and it was observed that both heads appeared 125 times. If two coins are tossed simultaneously at random, what is the probability of getting both heads?

(i)

5
6
(ii)

1
(iii)

1
6
(iv)

2
3
(v)

6
7

Question 4

4.

Two coins are tossed simultaneously 120 times and it was observed that both tails appeared 95 times. If two coins are tossed simultaneously at random, what is the probability of getting both tails?

(i)

4
5
(ii)

5
6
(iii)

19
24
(iv)

5
24
(v)

3
4

Question 5

5.

A die is thrown 70 times. Prime numbers appeared on the upper face 40 times. If a die is thrown at random, what is the probability of getting a prime number?

(i)

5
8
(ii)

5
7
(iii)

3
7
(iv)

4
7

Question 6

6.

A survey of 80 men showed that only 20 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)

0
(ii)

1
2
(iii)

1
4
(iv)

3
4
(v)

2
5

Question 7

7.

On a particular day, at a crossing in a city, the various types of 120 vehicles going past during a time-interval were observed as under:

Type of Vehicle

Two-wheeler

Four-wheeler

Three-wheeler

Frequency

25

45

50

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

(i)

5
12
(ii)

6
13
(iii)

1
2
(iv)

1
3
(v)

7
12

Question 8

8.

The following table shows the blood-groups of 486 students of a class.

Blood group

O

B

A

AB

Number of students

54

126

144

162

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

(i)

8
9
(ii)

2
9
(iii)

1
5
(iv)

0
(v)

1
9

Question 9

9.

There are 64 students in a class room of whom 36 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)

1
2
(ii)

10
17
(iii)

7
16
(iv)

5
8
(v)

9
16

Question 10

10.

There are 62 students in a class room of whom 36 are boys and 26 are girls. From these students, one is choosen at random. What is the probability that the choosen student is a girl ?

(i)

7
16
(ii)

18
31
(iii)

13
31
(iv)

14
31
(v)

12
31

Question 11

11.

In a lottery, there are 29 prizes and 17 blanks. What is the probability of getting a prize?

(i)

17
46
(ii)

14
23
(iii)

30
47
(iv)

29
46
(v)

15
23

Question 12

12.

In a lottery, there are 30 prizes and 20 blanks. What is the probability of not getting a prize?

(i)

2
5
(ii)

1
2
(iii)

3
5
(iv)

1
5

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 ball is hit. It reaches the boundary or not
c)	A baby is born. It is a boy or girl
d)	A man throws a die. The number on the top is either 1 or not 1
e)	A man starts his vehicle. It starts or it does not starts

(i)

{b,a}
(ii)

{a,c}
(iii)

{e,b,a}
(iv)

{d,c}
(v)

{d,c,a}

Question 14

14.

Which of the following are possible values of probability?

a)

8

3

b)

3

c)

-4.4

d)

0.4

e)

7

8

(i)

{a,d}
(ii)

{d,e}
(iii)

{b,e}
(iv)

{b,e,d}
(v)

{c,a,d}

Question 15

15.

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

(i)

7.33
(ii)

1.33
(iii)

2.33
(iv)

0.33
(v)

8.33

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 impossible event is 1
c)	The probability of an unsure event is 0
d)	The probability of a sure event is 1
e)	The probability of an imposible event can be > 1

(i)

{e,b,a}
(ii)

{c,d}
(iii)

{c,d,a}
(iv)

{a,d}
(v)

{b,a}

Question 17

17.

Which of the following are true?

a)

P(E) + P(
E
) = 0

b)

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

c)

P(E) - P(
E
) = 0

d)

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

e)

P(E) = 1 - P(
E
)

(i)

{d,a,b}
(ii)

{b,e}
(iii)

{a,b}
(iv)

{c,e}
(v)

{c,e,b}

Question 18

18.

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

(i)

5
6
(ii)

3
4
(iii)

1
2
(iv)

2
3
(v)

4
5

Question 19

19.

A die is thrown 340 times. The number 5 appears on the upper face 64 times. Now the die is thrown at random. What is the probability of getting a 5 ?

(i)

1
5
(ii)

69
85
(iii)

17
86
(iv)

16
85
(v)

3
17

Question 20

20.

333 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

99

108

126

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

(i)

26
37
(ii)

12
37
(iii)

10
37
(iv)

11
37
(v)

6
19

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

35

60

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

(i)

2
5
(ii)

4
5
(iii)

1
3
(iv)

1
5
(v)

0

Question 22

22.

A die is thrown 355 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

30

35

80

85

100

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

(i)

7
71
(ii)

64
71
(iii)

6
71
(iv)

8
71
(v)

1
9

Question 23

23.

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

21

9

7

16

12

7

13

10

5

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

(i)

8
9
(ii)

7
9
(iii)

2
3
(iv)

2
9
(v)

4
5

Question 24

24.

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

10

27

15

21

16

18

14

17

24

14

3

27

13

What is the empirical probability that an engineer lives greater than 3 km from her place of work?

(i)

1
13
(ii)

13
14
(iii)

11
13
(iv)

12
13
(v)

1

Assignment Key