EduSahara™ Worksheet

Question 1

1.

Which of the following are possible values of probability?

a)

9

2

b)

1

6

c)

0.75

d)

5

e)

-1.1

(i)

{b,c}
(ii)

{d,c}
(iii)

{d,c,b}
(iv)

{e,a,b}
(v)

{a,b}

Question 2

2.

On a particular day, at a crossing in a city, the various types of 105 vehicles going past during a time-interval were observed as under:

Type of Vehicle

Three-wheeler

Two-wheeler

Four-wheeler

Frequency

25

30

50

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

(i)

2
7
(ii)

5
21
(iii)

3
11
(iv)

16
21
(v)

4
21

Question 3

3.

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

18

19

11

13

15

16

19

10

23

18

27

22

What is the empirical probability that an engineer lives greater than 10 km from her place of work?

(i)

12
13
(ii)

1
12
(iii)

1
(iv)

11
12
(v)

5
6

Question 4

4.

A die is thrown 300 times. The number 3 appears on the upper face 60 times. Now the die is thrown at random. What is the probability of getting a 3 ?

(i)

4
5
(ii)

2
5
(iii)

1
5
(iv)

1
3
(v)

0

Question 5

5.

In a lottery, there are 25 prizes and 19 blanks. What is the probability of not getting a prize?

(i)

5
11
(ii)

19
44
(iii)

25
44
(iv)

4
9
(v)

9
22

Question 6

6.

Which of the following are true?

a)

P(E) = 1 - P(
E
)

b)

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

c)

P(E) - P(
E
) = 0

d)

P(E) + P(
E
) = 0

e)

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

(i)

{d,b}
(ii)

{a,b}
(iii)

{d,b,a}
(iv)

{e,c,a}
(v)

{c,a}

Question 7

7.

A survey of 60 men showed that only 40 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)

3
4
(ii)

1
3
(iii)

1
(iv)

2
3

Question 8

8.

A die is thrown 40 times. Prime numbers appeared on the upper face 30 times. If a die is thrown at random, what is the probability of getting a prime number?

(i)

1
4
(ii)

4
5
(iii)

3
4
(iv)

1
(v)

1
2

Question 9

9.

If P(E) =
0.25
, find P(
E
)

(i)

0.75
(ii)

7.75
(iii)

1.75
(iv)

8.75
(v)

2.75

Question 10

10.

Three coins are tossed simultaneously 240 times with the following frequencies of different outcomes :

Outcome

3 heads

2 heads

1 heads

No heads

Frequency

35

55

70

80

If the three coins are simultaneously tossed again, compute the probability of '1 heads' coming up.

(i)

1
3
(ii)

7
24
(iii)

1
4
(iv)

8
25
(v)

17
24

Question 11

11.

A coin is tossed 80 times and tail appears 40 times. If the coin is tossed again, what is the probability of getting a head?

(i)

5
6
(ii)

4
5
(iii)

2
3
(iv)

1
2
(v)

3
4

Question 12

12.

A coin is tossed 60 times and head appears 45 times. If the coin is tossed again, what is the probability of getting a tail?

(i)

1
4
(ii)

0
(iii)

2
5
(iv)

1
2
(v)

3
4

Question 13

13.

In a lottery, there are 14 prizes and 13 blanks. What is the probability of getting a prize?

(i)

5
9
(ii)

14
27
(iii)

15
28
(iv)

13
27

Question 14

14.

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

17

30

7

17

13

12

2

9

21

15

13

27

14

What is the empirical probability that an engineer lives less than 13 km from her place of work?

(i)

5
14
(ii)

3
13
(iii)

9
13
(iv)

5
13
(v)

4
13

Question 15

15.

Which of the following experiments have equally likely outcomes?

a)	A baby is born. It is a boy or girl
b)	A true/false question is attempted. The answer is either right or wrong
c)	A man throws a die. The number on the top is either 2 or not 2
d)	A ball is hit. It reaches the boundary or not
e)	A man starts his vehicle. It starts or it does not starts

(i)

{c,a}
(ii)

{d,b}
(iii)

{e,c,a}
(iv)

{a,b}
(v)

{d,b,a}

Question 16

16.

Two players Ravali and Geetika play a tennis match. It is known that the probability of Ravali winning the match is 0.67. What is the probability of Geetika winning the match?

(i)

33
100
(ii)

8
25
(iii)

17
50
(iv)

67
100
(v)

34
101

Question 17

17.

324 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

63

117

144

Compute the probability of the family, chosen at random, having 1 girl.

(i)

14
37
(ii)

13
36
(iii)

23
36
(iv)

1
3
(v)

7
18

Question 18

18.

Which of the following are true?

a)	The probability of an impossible event is 1
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 unsure event is 0
e)	The probability of a sure event is 1

(i)

{c,e}
(ii)

{c,e,b}
(iii)

{d,a,b}
(iv)

{b,e}
(v)

{a,b}

Question 19

19.

Two coins are tossed simultaneously 90 times and it was observed that both tails appeared 60 times. If two coins are tossed simultaneously at random, what is the probability of getting both tails?

(i)

2
3
(ii)

1
3
(iii)

3
4
(iv)

1

Question 20

20.

There are 62 students in a class room of whom 32 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)

15
31
(ii)

1
2
(iii)

14
31
(iv)

16
31

Question 21

21.

The following table shows the blood-groups of 414 students of a class.

Blood group

AB

A

B

O

Number of students

63

108

117

126

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

(i)

6
23
(ii)

7
24
(iii)

17
23
(iv)

7
23
(v)

5
23

Question 22

22.

Two coins are tossed simultaneously 60 times and it was observed that both heads appeared 35 times. If two coins are tossed simultaneously at random, what is the probability of getting both heads?

(i)

5
12
(ii)

7
12
(iii)

1
2
(iv)

2
3
(v)

8
13

Question 23

23.

There are 66 students in a class room of whom 34 are boys and 32 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)

16
33
(iii)

17
33
(iv)

9
17

Question 24

24.

Two coins are tossed simultaneously 130 times and it was observed that both tails appeared 60 times. If two coins are tossed simultaneously at random, what is the probability of getting both tails?

(i)

1
2
(ii)

7
13
(iii)

5
13
(iv)

6
13

Question 25

25.

A die is thrown 325 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

30

35

40

65

75

80

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

(i)

3
22
(ii)

9
65
(iii)

57
65
(iv)

8
65
(v)

7
65

Assignment Key