EduSahara™ Worksheet

Question 1

1.

A die is thrown 40 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)

5
6
(iii)

1
2
(iv)

3
4
(v)

4
5

Question 2

2.

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

2

1

21

6

19

17

30

15

What is the empirical probability that an engineer lives less than 6 km from her place of work?

(i)

1
2
(ii)

1
4
(iii)

0
(iv)

3
4
(v)

2
5

Question 3

3.

A die is thrown 300 times. The number 5 appears on the upper face 60 times. Now the die is thrown at random. What is the probability of getting a 5 ?

(i)

4
5
(ii)

2
5
(iii)

1
3
(iv)

1
5
(v)

0

Question 4

4.

A coin is tossed 80 times and tail appears 50 times. If the coin is tossed again, what is the probability of getting a head?

(i)

4
9
(ii)

1
2
(iii)

3
8
(iv)

1
4
(v)

5
8

Question 5

5.

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)

7
9
(ii)

1
3
(iii)

1
9
(iv)

3
10
(v)

2
9

Question 6

6.

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

2

21

23

3

30

16

10

9

24

20

17

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

(i)

6
11
(ii)

5
11
(iii)

7
11
(iv)

7
12

Question 7

7.

Which of the following are possible values of probability?

a)

8

7

b)

-2.3

c)

0.33

d)

2

7

e)

3

(i)

{b,d}
(ii)

{e,a,c}
(iii)

{c,d}
(iv)

{b,d,c}
(v)

{a,c}

Question 8

8.

In a lottery, there are 11 prizes and 19 blanks. What is the probability of getting a prize?

(i)

2
5
(ii)

19
30
(iii)

11
30
(iv)

12
31
(v)

1
3

Question 9

9.

270 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

99

126

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

(i)

2
5
(ii)

1
2
(iii)

8
15
(iv)

7
15

Question 10

10.

Which of the following experiments have equally likely outcomes?

a)	A ball is hit. It reaches the boundary or not
b)	A man throws a die. The number on the top is either 3 or not 3
c)	A true/false question is attempted. The answer is either right or wrong
d)	A man starts his vehicle. It starts or it does not starts
e)	A baby is born. It is a boy or girl

(i)

{d,a,c}
(ii)

{b,e}
(iii)

{a,c}
(iv)

{b,e,c}
(v)

{c,e}

Question 11

11.

Two players Kamala and Pooja play a tennis match. It is known that the probability of Kamala winning the match is 0.57. What is the probability of Pooja winning the match?

(i)

44
101
(ii)

21
50
(iii)

43
100
(iv)

57
100
(v)

11
25

Question 12

12.

A survey of 130 men showed that only 120 of them know German. Out of these men, if one is selected at random, what is the probability that the selected man knows German?

(i)

1
13
(ii)

11
13
(iii)

13
14
(iv)

1
(v)

12
13

Question 13

13.

Two coins are tossed simultaneously 140 times and it was observed that both tails appeared 50 times. If two coins are tossed simultaneously at random, what is the probability of getting both tails?

(i)

9
14
(ii)

2
5
(iii)

3
7
(iv)

2
7
(v)

5
14

Question 14

14.

There are 66 students in a class room of whom 36 are boys and 30 are girls. From these students, one is choosen at random. What is the probability that the choosen student is a boy ?

(i)

6
11
(ii)

7
12
(iii)

5
11
(iv)

7
11

Question 15

15.

In a lottery, there are 11 prizes and 10 blanks. What is the probability of getting a prize?

(i)

10
21
(ii)

4
7
(iii)

11
21
(iv)

6
11

Question 16

16.

Which of the following are true?

a)

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

b)

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

c)

P(E) - P(
E
) = 0

d)

P(E) = 1 - P(
E
)

e)

P(E) + P(
E
) = 0

(i)

{e,a,b}
(ii)

{c,d,b}
(iii)

{c,d}
(iv)

{a,b}
(v)

{b,d}

Question 17

17.

Which of the following are true?

a)	The probability of an unsure event is 0
b)	For an event E, we have 0 ≤ P(E) ≤ 1
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)

{d,a,b}
(ii)

{a,b}
(iii)

{c,e}
(iv)

{b,e}
(v)

{c,e,b}

Question 18

18.

In a lottery, there are 27 prizes and 20 blanks. What is the probability of not getting a prize?

(i)

21
47
(ii)

20
47
(iii)

19
47
(iv)

7
16
(v)

27
47

Question 19

19.

Three coins are tossed simultaneously 185 times with the following frequencies of different outcomes :

Outcome

3 heads

2 heads

1 heads

No heads

Frequency

35

40

50

60

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

(i)

30
37
(ii)

8
37
(iii)

6
37
(iv)

4
19
(v)

7
37

Question 20

20.

On a particular day, at a crossing in a city, the various types of 140 vehicles going past during a time-interval were observed as under:

Type of Vehicle

Four-wheeler

Three-wheeler

Two-wheeler

Frequency

40

45

55

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

(i)

3
8
(ii)

2
7
(iii)

1
7
(iv)

3
7
(v)

5
7

Question 21

21.

A die is thrown 390 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

35

40

60

75

85

95

If the die is thrown again randomly, find the probability of getting 6 as outcome.

(i)

20
79
(ii)

59
78
(iii)

10
39
(iv)

3
13
(v)

19
78

Question 22

22.

If P(E) =
0.33
, find P(
E
)

(i)

0.67
(ii)

2.67
(iii)

7.67
(iv)

1.67
(v)

8.67

Question 23

23.

There are 60 students in a class room of whom 24 are boys and 36 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)

2
3
(iii)

4
5
(iv)

2
5

Question 24

24.

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

Blood group

O

A

AB

B

Number of students

54

81

90

99

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

(i)

1
3
(ii)

2
9
(iii)

6
19
(iv)

13
18
(v)

5
18

Question 25

25.

Two coins are tossed simultaneously 130 times and it was observed that both heads appeared 20 times. If two coins are tossed simultaneously at random, what is the probability of getting both heads?

(i)

11
13
(ii)

2
13
(iii)

1
13
(iv)

3
14
(v)

3
13

Assignment Key