EduSahara™ Worksheet

Question 1

1.

In a lottery, there are 24 prizes and 15 blanks. What is the probability of not getting a prize?

(i)

4
13
(ii)

6
13
(iii)

5
13
(iv)

3
7
(v)

8
13

Question 2

2.

Which of the following are possible values of probability?

a)

4

5

b)

-4.3

c)

0.67

d)

9

7

e)

5

(i)

{e,b,a}
(ii)

{b,a}
(iii)

{d,c,a}
(iv)

{a,c}
(v)

{d,c}

Question 3

3.

Two players Rizvana and Meena play a tennis match. It is known that the probability of Rizvana winning the match is 0.22. What is the probability of Meena winning the match?

(i)

19
25
(ii)

4
5
(iii)

11
50
(iv)

40
51
(v)

39
50

Question 4

4.

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

72

108

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

(i)

12
25
(ii)

11
25
(iii)

1
2
(iv)

13
25

Question 5

5.

A die is thrown 250 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

40

55

65

If the die is thrown again randomly, find the probability of getting 5 as outcome.

(i)

4
17
(ii)

11
50
(iii)

39
50
(iv)

6
25
(v)

1
5

Question 6

6.

Two coins are tossed simultaneously 140 times and it was observed that both heads appeared 100 times. If two coins are tossed simultaneously at random, what is the probability of getting both heads?

(i)

3
4
(ii)

4
7
(iii)

6
7
(iv)

5
7
(v)

2
7

Question 7

7.

Which of the following are true?

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

(i)

{a,c}
(ii)

{e,a,c}
(iii)

{b,d}
(iv)

{b,d,c}
(v)

{c,d}

Question 8

8.

If P(E) =
0.78
, find P(
E
)

(i)

7.22
(ii)

2.22
(iii)

8.22
(iv)

1.22
(v)

0.22

Question 9

9.

The following table shows the blood-groups of 405 students of a class.

Blood group

A

AB

O

B

Number of students

54

99

117

135

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

(i)

1
5
(ii)

3
16
(iii)

13
15
(iv)

2
15
(v)

1
15

Question 10

10.

A die is thrown 540 times. The number 3 appears on the upper face 84 times. Now the die is thrown at random. What is the probability of getting a 3 ?

(i)

38
45
(ii)

8
45
(iii)

2
15
(iv)

4
23
(v)

7
45

Question 11

11.

A survey of 150 men showed that only 65 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)

14
31
(ii)

2
5
(iii)

13
30
(iv)

17
30
(v)

7
15

Question 12

12.

Three coins are tossed simultaneously 260 times with the following frequencies of different outcomes :

Outcome

3 heads

2 heads

1 heads

No heads

Frequency

40

65

75

80

If the three coins are simultaneously tossed again, compute the probability of 'No heads' coming up.

(i)

3
13
(ii)

5
14
(iii)

4
13
(iv)

9
13
(v)

5
13

Question 13

13.

Two coins are tossed simultaneously 120 times and it was observed that both tails appeared 20 times. If two coins are tossed simultaneously at random, what is the probability of getting both tails?

(i)

2
7
(ii)

1
6
(iii)

1
3
(iv)

0
(v)

5
6

Question 14

14.

A coin is tossed 50 times and head appears 45 times. If the coin is tossed again, what is the probability of getting a tail?

(i)

0
(ii)

2
11
(iii)

1
5
(iv)

1
10
(v)

9
10

Question 15

15.

On a particular day, at a crossing in a city, the various types of 145 vehicles going past during a time-interval were observed as under:

Type of Vehicle

Four-wheeler

Two-wheeler

Three-wheeler

Frequency

40

50

55

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

(i)

12
29
(ii)

11
29
(iii)

2
5
(iv)

18
29
(v)

10
29

Question 16

16.

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

16

16

30

27

26

29

11

11

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

(i)

1
(ii)

1
4
(iii)

3
4
(iv)

1
2
(v)

4
5

Question 17

17.

A die is thrown 110 times. Prime numbers appeared on the upper face 25 times. If a die is thrown at random, what is the probability of getting a prime number?

(i)

2
11
(ii)

3
11
(iii)

17
22
(iv)

5
22
(v)

6
23

Question 18

18.

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)

{b,e}
(ii)

{d,a,b}
(iii)

{c,e}
(iv)

{a,b}
(v)

{c,e,b}

Question 19

19.

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

16

14

24

30

13

25

30

21

23

What is the empirical probability that an engineer lives less than 14 km from her place of work?

(i)

1
9
(ii)

8
9
(iii)

0
(iv)

1
5
(v)

2
9

Question 20

20.

There are 52 students in a class room of whom 20 are boys and 32 are girls. From these students, one is choosen at random. What is the probability that the choosen student is a girl ?

(i)

9
13
(ii)

5
13
(iii)

7
13
(iv)

9
14
(v)

8
13

Question 21

21.

There are 58 students in a class room of whom 30 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)

14
29
(ii)

16
29
(iii)

8
15
(iv)

15
29

Question 22

22.

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 man starts his vehicle. It starts or it does not starts
c)	A ball is hit. It reaches the boundary or not
d)	A man throws a die. The number on the top is either 2 or not 2
e)	A baby is born. It is a boy or girl

(i)

{a,e}
(ii)

{d,b,a}
(iii)

{c,e}
(iv)

{b,a}
(v)

{c,e,a}

Question 23

23.

In a lottery, there are 29 prizes and 13 blanks. What is the probability of getting a prize?

(i)

2
3
(ii)

5
7
(iii)

29
42
(iv)

13
42
(v)

30
43

Question 24

24.

A die is thrown 400 times. The number 3 appears on the upper face 78 times. Now the die is thrown at random. What is the probability of getting a 3 ?

(i)

1
5
(ii)

40
201
(iii)

19
100
(iv)

39
200
(v)

161
200

Question 25

25.

A coin is tossed 80 times and tail appears 45 times. If the coin is tossed again, what is the probability of getting a head?

(i)

8
17
(ii)

3
8
(iii)

1
2
(iv)

9
16
(v)

7
16

Assignment Key