EduSahara™ Worksheet

Question 1

1.

There are 70 students in a class room of whom 38 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)

17
35
(ii)

19
35
(iii)

17
36
(iv)

3
7
(v)

16
35

Question 2

2.

56 cards are numbered 1,2,3,....56 and put in a box and mixed thoroughly. A card is drawn at random. What is the probability that the number on the drawn card is greater then 12?

(i)

5
7
(ii)

3
14
(iii)

11
14
(iv)

4
5
(v)

6
7

Question 3

3.

Three unbiased coins are tossed simultaneously. Find the probability of getting exactly one head.

(i)

1
4
(ii)

1
2
(iii)

5
8
(iv)

4
9
(v)

3
8

Question 4

4.

Two unbiased dice are thrown simultaneously. Find the probability of getting a doublet.

(i)

0
(ii)

5
6
(iii)

1
6
(iv)

1
3
(v)

2
7

Question 5

5.

When two dice are thrown simultaneously, how many elementary events are possible?

(i)

36
(ii)

37
(iii)

35
(iv)

34
(v)

39

Question 6

6.

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

(i)

33
100
(ii)

8
25
(iii)

67
100
(iv)

34
101
(v)

17
50

Question 7

7.

An unbiased die is thrown once. Find the probability of getting a 5?

(i)

2
7
(ii)

1
6
(iii)

0
(iv)

1
3
(v)

5
6

Question 8

8.

95 cards are numbered 1,2,3,....95 and put in a box and mixed thoroughly. A card is drawn at random. What is the probability that the number on the drawn card is an odd number?

(i)

48
95
(ii)

49
96
(iii)

47
95
(iv)

49
95

Question 9

9.

Three unbiased coins are tossed simultaneously. Find the probability of getting at least one head.

(i)

7
8
(ii)

1
8
(iii)

3
4
(iv)

1
(v)

8
9

Question 10

10.

71 cards are numbered 1,2,3,....71 and put in a box and mixed thoroughly. A card is drawn at random. What is the probability that the number on the drawn card is a prime number?

(i)

21
71
(ii)

20
71
(iii)

7
24
(iv)

51
71
(v)

19
71

Question 11

11.

A box contains 70 discs which are numbered from 1 to 70. If one disc is drawn at random from the box, find the probability that it bears a perfect square number.

(i)

5
36
(ii)

4
35
(iii)

31
35
(iv)

3
35
(v)

1
7

Question 12

12.

A lot of 27 bulbs contain 3 defective ones. One bulb is drawn at random from the lot. Suppose the bulb drawn is not defective and is not replaced. Now one bulb is drawn at random from the rest. What is the probability that this bulb is not defective ?

(i)

11
13
(ii)

23
26
(iii)

12
13
(iv)

3
26
(v)

8
9

Question 13

13.

A carton consist of 83 shirts of which 71 are good, 8 have minor defects and 4 have major defects. Kumar, a trader, will only accept the shirts which are good, but Karishma, another trader, will only reject the shirts which have major defects. One shirt is drawn at random from the carton. What is the probability that it is acceptable to Karishma?

(i)

20
21
(ii)

4
83
(iii)

79
83
(iv)

80
83
(v)

78
83

Question 14

14.

Two unbiased dice are thrown simultaneously. Find the probability of getting at least 9 as the sum of the two numbers on the dice.

(i)

2
9
(ii)

5
18
(iii)

6
19
(iv)

13
18
(v)

1
3

Question 15

15.

One card is drawn at random from a well shuffled deck of 52 cards. What is the probability that the card drawn is a queen of spades?

(i)

1
26
(ii)

1
13
(iii)

1
4
(iv)

3
13
(v)

1
52

Question 16

16.

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

30

35

55

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

(i)

8
25
(ii)

17
24
(iii)

1
4
(iv)

7
24
(v)

1
3

Question 17

17.

A lot of 28 bulbs contain 5 defective ones. One bulb is drawn at random from the lot. What is the probability that this bulb is defective ?

(i)

23
28
(ii)

6
29
(iii)

3
14
(iv)

1
7
(v)

5
28

Question 18

18.

Three unbiased coins are tossed simultaneously. Find the probability of getting at least two heads.

(i)

3
4
(ii)

5
6
(iii)

2
3
(iv)

4
5
(v)

1
2

Question 19

19.

Three coins are tossed simultaneously 175 times with the following frequencies of different outcomes :

Outcome

3 heads

2 heads

1 heads

No heads

Frequency

25

40

50

60

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

(i)

2
7
(ii)

5
7
(iii)

3
7
(iv)

3
8
(v)

1
7

Question 20

20.

89 cards are numbered 1,2,3,....89 and put in a box and mixed thoroughly. A card is drawn at random. What is the probability that the number on the drawn card is less then 21?

(i)

7
30
(ii)

20
89
(iii)

19
89
(iv)

21
89
(v)

69
89

Question 21

21.

A bag contains 36 blue balls, 40 orange balls, 20 pink balls and 60 white balls. One ball is drawn at random from the bag. Find the probability that the ball drawn is blue or white.

(i)

7
13
(ii)

9
13
(iii)

5
13
(iv)

9
14
(v)

8
13

Question 22

22.

A die is thrown 400 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

55

60

70

85

105

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

(i)

21
80
(ii)

11
40
(iii)

59
80
(iv)

22
81
(v)

1
4

Question 23

23.

A single unbiased coin is tossed. Find the probability of getting a head.

(i)

5
6
(ii)

3
4
(iii)

2
3
(iv)

4
5
(v)

1
2

Question 24

24.

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)

1
2
(ii)

9
16
(iii)

3
8
(iv)

7
16
(v)

8
17

Question 25

25.

Which of the following are true?

a)	The probability of an event that cannot happen is unknown
b)	Probability of getting 107 marks out of 100 is 1.07
c)	The probability of an event that is very likely to happen is 1
d)	If the probability of failing the exam is 0.5, the probability of passing the exam is 0.5
e)	If the probability is too less, it will become negative

(i)

{a,d}
(ii)

{c,e,d}
(iii)

{d}
(iv)

{b,d}

Assignment Key