EduSahara™ Worksheet

Question 1

1.

In a lottery, there are 12 prizes and 11 blanks. What is the probability of not getting a prize?

(i)

11
23
(ii)

12
23
(iii)

10
23
(iv)

1
2

Question 2

2.

180 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

81

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

(i)

1
2
(ii)

10
21
(iii)

11
20
(iv)

9
20
(v)

2
5

Question 3

3.

Which of the following experiments have equally likely outcomes?

a)	A man throws a die. The number on the top is either 4 or not 4
b)	A true/false question is attempted. The answer is either right or wrong
c)	A baby is born. It is a boy or girl
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)

{d,c,b}
(ii)

{a,b}
(iii)

{d,c}
(iv)

{b,c}
(v)

{e,a,b}

Question 4

4.

Two players Aishwarya and Swathi play a tennis match. It is known that the probability of Aishwarya winning the match is 0.12. What is the probability of Swathi winning the match?

(i)

22
25
(ii)

23
25
(iii)

21
25
(iv)

23
26
(v)

3
25

Question 5

5.

A die is thrown 370 times. The number 2 appears on the upper face 62 times. Now the die is thrown at random. What is the probability of getting a 2 ?

(i)

31
185
(ii)

6
37
(iii)

16
93
(iv)

32
185
(v)

154
185

Question 6

6.

On a particular day, at a crossing in a city, the various types of 150 vehicles going past during a time-interval were observed as under:

Type of Vehicle

Four-wheeler

Two-wheeler

Three-wheeler

Frequency

45

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)

11
30
(ii)

2
5
(iii)

19
30
(iv)

12
31
(v)

1
3

Question 7

7.

In a lottery, there are 21 prizes and 14 blanks. What is the probability of getting a prize?

(i)

2
3
(ii)

2
5
(iii)

4
5
(iv)

3
5

Question 8

8.

Two coins are tossed simultaneously 120 times and it was observed that both tails appeared 40 times. If two coins are tossed simultaneously at random, what is the probability of getting both tails?

(i)

1
3
(ii)

1
2
(iii)

0
(iv)

2
3

Question 9

9.

A coin is tossed 40 times and tail appears 30 times. If the coin is tossed again, what is the probability of getting a head?

(i)

3
4
(ii)

1
4
(iii)

2
5
(iv)

0
(v)

1
2

Question 10

10.

There are 48 students in a class room of whom 24 are boys and 24 are girls. From these students, one is choosen at random. What is the probability that the choosen student is a boy ?

(i)

4
5
(ii)

3
4
(iii)

5
6
(iv)

1
2
(v)

2
3

Question 11

11.

Three coins are tossed simultaneously 140 times with the following frequencies of different outcomes :

Outcome

3 heads

2 heads

1 heads

No heads

Frequency

25

30

40

45

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

(i)

6
29
(ii)

5
28
(iii)

1
7
(iv)

23
28
(v)

3
14

Question 12

12.

Two coins are tossed simultaneously 60 times and it was observed that both heads appeared 40 times. If two coins are tossed simultaneously at random, what is the probability of getting both heads?

(i)

1
3
(ii)

2
3
(iii)

1
(iv)

3
4

Question 13

13.

The following table shows the blood-groups of 387 students of a class.

Blood group

O

A

B

AB

Number of students

45

63

135

144

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

(i)

14
43
(ii)

15
43
(iii)

16
43
(iv)

4
11
(v)

28
43

Question 14

14.

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

40

55

65

70

80

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

(i)

11
67
(ii)

12
67
(iii)

3
17
(iv)

10
67
(v)

56
67

Question 15

15.

A die is thrown 40 times. Prime numbers appeared on the upper face 35 times. If a die is thrown at random, what is the probability of getting a prime number?

(i)

8
9
(ii)

7
8
(iii)

3
4
(iv)

1
(v)

1
8

Question 16

16.

A survey of 130 men showed that only 20 of them know Spanish. Out of these men, if one is selected at random, what is the probability that the selected man knows Spanish?

(i)

2
13
(ii)

3
13
(iii)

11
13
(iv)

1
13
(v)

3
14

Question 17

17.

There are 60 students in a class room of whom 36 are boys and 24 are girls. From these students, one is choosen at random. What is the probability that the choosen student is a girl ?

(i)

1
5
(ii)

2
5
(iii)

3
5
(iv)

1
2

Question 18

18.

If P(E) =
0.38
, find P(
E
)

(i)

1.62
(ii)

0.62
(iii)

8.62
(iv)

7.62
(v)

2.62

Question 19

19.

Which of the following are true?

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

(i)

{a,d}
(ii)

{d,e}
(iii)

{c,a,d}
(iv)

{b,e}
(v)

{b,e,d}

Question 20

20.

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

17

25

14

4

25

15

9

25

What is the empirical probability that an engineer lives less than 25 km from her place of work?

(i)

3
4
(ii)

2
3
(iii)

3
8
(iv)

5
8
(v)

1
2

Question 21

21.

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

17

9

10

1

14

30

24

7

30

5

8

3

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

(i)

2
5
(ii)

1
4
(iii)

0
(iv)

1
2
(v)

3
4

Question 22

22.

A coin is tossed 60 times and head appears 25 times. If the coin is tossed again, what is the probability of getting a tail?

(i)

5
12
(ii)

7
12
(iii)

8
13
(iv)

2
3
(v)

1
2

Question 23

23.

On a particular day, at a crossing in a city, the various types of 115 vehicles going past during a time-interval were observed as under:

Type of Vehicle

Two-wheeler

Four-wheeler

Three-wheeler

Frequency

25

40

50

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)

15
23
(iii)

9
23
(iv)

7
23
(v)

8
23

Question 24

24.

Which of the following are true?

a)

P(E) + P(
E
) = 0

b)

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

c)

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

d)

P(E) - P(
E
) = 0

e)

P(E) = 1 - P(
E
)

(i)

{c,e}
(ii)

{d,a,c}
(iii)

{a,c}
(iv)

{b,e,c}
(v)

{b,e}

Question 25

25.

Which of the following are possible values of probability?

a)

2

b)

4

3

c)

-3.1

d)

1

5

e)

0.5

(i)

{d,e}
(ii)

{b,e}
(iii)

{c,a,d}
(iv)

{a,d}
(v)

{b,e,d}

Assignment Key