EduSahara™ Worksheet

Question 1

1.

Two coins are tossed simultaneously 130 times and it was observed that both heads appeared 65 times. If two coins are tossed simultaneously at random, what is the probability of getting both heads?

(i)

1
2
(ii)

4
5
(iii)

3
4
(iv)

2
3
(v)

5
6

Question 2

2.

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 two-digit number.

(i)

9
70
(ii)

6
7
(iii)

62
71
(iv)

31
35
(v)

61
70

Question 3

3.

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

(i)

4
5
(ii)

1
2
(iii)

2
3
(iv)

3
4
(v)

5
6

Question 4

4.

A box contains 30 discs which are numbered from 1 to 30. If one disc is drawn at random from the box, find the probability that it bears a number divisible by 5.

(i)

1
3
(ii)

2
5
(iii)

0
(iv)

1
5
(v)

4
5

Question 5

5.

Which of the following are true?

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

(i)

{d,a,c}
(ii)

{c,e}
(iii)

{b,e,c}
(iv)

{a,c}
(v)

{b,e}

Question 6

6.

An unbiased die is thrown once. Find the probability of getting a number between 2 and 6?

(i)

1
2
(ii)

4
5
(iii)

3
4
(iv)

5
6
(v)

2
3

Question 7

7.

What is the probability of a sure event?

(i)

1
4
(ii)

1
2
(iii)

1
(iv)

0
(v)

3
4

Question 8

8.

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

28

28

10

2

26

2

13

13

28

2

12

19

What is the empirical probability that an engineer lives greater than 28 km from her place of work?

(i)

1
2
(ii)

1
4
(iii)

0
(iv)

3
4
(v)

1

Question 9

9.

There are 64 students in a class room of whom 26 are boys and 38 are girls. From these students, one is choosen at random. What is the probability that the choosen student is a boy ?

(i)

19
32
(ii)

3
8
(iii)

7
16
(iv)

13
32
(v)

14
33

Question 10

10.

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

(i)

1
13
(ii)

1
52
(iii)

1
26
(iv)

3
13
(v)

1
4

Question 11

11.

A coin is tossed 100 times and tail appears 65 times. If the coin is tossed again, what is the probability of getting a head?

(i)

7
20
(ii)

2
5
(iii)

3
10
(iv)

8
21
(v)

13
20

Question 12

12.

In a musical chair game, the person playing the music has been advised to stop playing the music at any time with in 2 minutes after she starts playing. What is the probabilty that the music will stop within the first half-minute after starting?

(i)

1
2
(ii)

3
4
(iii)

0
(iv)

2
5
(v)

1
4

Question 13

13.

A bag contains 33 blue balls, 15 yellow balls, 9 pink balls and 30 black balls. One ball is drawn at random from the bag. Find the probability that the ball drawn is not black.

(i)

18
29
(ii)

19
29
(iii)

10
29
(iv)

20
29
(v)

2
3

Question 14

14.

A survey of 60 men showed that only 20 of them know Urdu. Out of these men, if one is selected at random, what is the probability that the selected man knows Urdu?

(i)

0
(ii)

2
3
(iii)

1
2
(iv)

1
3

Question 15

15.

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

(i)

3
4
(ii)

5
6
(iii)

1
2
(iv)

2
3
(v)

4
5

Question 16

16.

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 divisible by 5?

(i)

2
5
(ii)

0
(iii)

1
3
(iv)

1
5
(v)

4
5

Question 17

17.

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 greater then 18?

(i)

54
71
(ii)

53
71
(iii)

52
71
(iv)

3
4
(v)

18
71

Question 18

18.

One card is drawn at random from a well shuffled deck of 52 cards. What is the probability that the card drawn is '5' of spades?

(i)

1
4
(ii)

3
13
(iii)

1
13
(iv)

1
52
(v)

1
26

Question 19

19.

The following table shows the blood-groups of 243 students of a class.

Blood group

AB

B

A

O

Number of students

45

54

63

81

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

(i)

8
27
(ii)

7
27
(iii)

2
7
(iv)

20
27
(v)

2
9

Question 20

20.

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

(i)

37
(ii)

36
(iii)

35
(iv)

38
(v)

33

Question 21

21.

A bag contains 70 blue marbles, 60 black marbles, 70 pink marbles and 35 orange marbles. One marble is drawn at random from the bag. Find the probability that the marble drawn is neither black nor pink.

(i)

22
47
(ii)

11
24
(iii)

20
47
(iv)

21
47
(v)

26
47

Question 22

22.

An unbiased die is thrown once. Find the probability of getting a 2?

(i)

1
3
(ii)

0
(iii)

2
7
(iv)

1
6
(v)

5
6

Question 23

23.

Two coins are tossed simultaneously 110 times and it was observed that both tails appeared 70 times. If two coins are tossed simultaneously at random, what is the probability of getting both tails?

(i)

2
3
(ii)

8
11
(iii)

4
11
(iv)

6
11
(v)

7
11

Question 24

24.

Two unbiased dice are thrown simultaneously. Find the probability of getting 4 as the sum of the two numbers on the dice.

(i)

1
12
(ii)

0
(iii)

1
6
(iv)

11
12
(v)

2
13

Question 25

25.

62 cards are numbered 1,2,3,....62 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 12?

(i)

5
31
(ii)

11
62
(iii)

4
21
(iv)

6
31
(v)

51
62

Assignment Key