EduSahara™ Worksheet

Question 1

1.

A bag contains 6 orange marbles, 36 pink marbles, 12 blue marbles and 21 yellow marbles. One marble is drawn at random from the bag. Find the probability that the marble drawn is pink or yellow.

(i)

10
13
(ii)

6
25
(iii)

19
25
(iv)

4
5
(v)

18
25

Question 2

2.

Which of the following are true?

a)	The probability of an event that is very likely to happen is 1
b)	If the probability is too less, it will become negative
c)	If the probability of failing the exam is 0.33, the probability of passing the exam is 0.67
d)	The probability of an event that cannot happen is unknown
e)	Probability of getting 109 marks out of 100 is 1.09

(i)

{d,e,c}
(ii)

{b,c}
(iii)

{c}
(iv)

{a,c}

Question 3

3.

Three coins are tossed simultaneously 205 times with the following frequencies of different outcomes :

Outcome

3 heads

2 heads

1 heads

No heads

Frequency

25

40

55

85

If the three coins are simultaneously tossed again, compute the probability of '2 heads' coming up.

(i)

33
41
(ii)

3
14
(iii)

8
41
(iv)

7
41
(v)

9
41

Question 4

4.

A lot of 25 bulbs contain 6 defective ones. One bulb is drawn at random from the lot. What is the probability that this bulb is defective ?

(i)

7
26
(ii)

7
25
(iii)

19
25
(iv)

6
25
(v)

1
5

Question 5

5.

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

(i)

3
4
(ii)

7
8
(iii)

1
(iv)

8
9
(v)

1
8

Question 6

6.

An unbiased die is thrown once. Find the probability of getting an even number?

(i)

2
3
(ii)

1
2
(iii)

4
5
(iv)

5
6
(v)

3
4

Question 7

7.

A die is thrown 245 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

30

35

45

50

60

If the die is thrown again randomly, find the probability of getting 2 as outcome.

(i)

5
49
(ii)

43
49
(iii)

1
7
(iv)

7
50
(v)

6
49

Question 8

8.

A game consists of tossing a coin 3 times and noting its outcome each time. Jimmy wins if all the tosses give the same result i.e., three heads or three tails, and loses otherwise. Calculate the probability that Jimmy will lose the game.

(i)

1
4
(ii)

3
4
(iii)

1
(iv)

4
5
(v)

1
2

Question 9

9.

A carton consist of 92 shirts of which 75 are good, 15 have minor defects and 2 have major defects. Akbar, a trader, will only accept the shirts which are good, but Anu, 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 Akbar?

(i)

17
92
(ii)

19
23
(iii)

76
93
(iv)

75
92
(v)

37
46

Question 10

10.

Which of the following are true?

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

(i)

{a,b}
(ii)

{b,e}
(iii)

{c,e}
(iv)

{c,e,b}
(v)

{d,a,b}

Question 11

11.

A die is thrown 140 times. Prime numbers appeared on the upper face 130 times. If a die is thrown at random, what is the probability of getting a prime number?

(i)

6
7
(ii)

14
15
(iii)

1
14
(iv)

1
(v)

13
14

Question 12

12.

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

(i)

1
2
(ii)

2
3
(iii)

5
6
(iv)

3
4
(v)

4
5

Question 13

13.

Two unbiased coins are tossed simultaneously. Find the probability of getting no head.

(i)

1
4
(ii)

3
4
(iii)

2
5
(iv)

1
2
(v)

0

Question 14

14.

Which of the following experiments have equally likely outcomes?

a)	A true/false question is attempted. The answer is either right or wrong
b)	A ball is hit. It reaches the boundary or not
c)	A man throws a die. The number on the top is either 5 or not 5
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)

{c,e}
(ii)

{b,a}
(iii)

{a,e}
(iv)

{c,e,a}
(v)

{d,b,a}

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 face card ?

(i)

3
13
(ii)

1
13
(iii)

1
26
(iv)

1
4
(v)

1
52

Question 16

16.

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

(i)

2
3
(ii)

4
5
(iii)

5
6
(iv)

3
4
(v)

1
2

Question 17

17.

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

(i)

3
4
(ii)

1
(iii)

2
3
(iv)

1
3

Question 18

18.

A die is thrown twice. What is the probability that 3 will not come up either time?

(i)

11
36
(ii)

26
37
(iii)

13
18
(iv)

25
36
(v)

2
3

Question 19

19.

171 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

72

Compute the probability of the family, chosen at random, having no girls.

(i)

4
19
(ii)

3
10
(iii)

6
19
(iv)

14
19
(v)

5
19

Question 20

20.

A bag contains 20 red balls, 50 pink balls, 45 blue balls and 55 yellow balls. One ball is drawn at random from the bag. Find the probability that the ball drawn is not yellow.

(i)

11
17
(ii)

12
17
(iii)

23
34
(iv)

11
34
(v)

24
35

Question 21

21.

One card is drawn at random from a well shuffled deck of 52 cards. What is the probability that the card drawn is either a red card or a jack?

(i)

1
26
(ii)

7
13
(iii)

3
13
(iv)

1
13
(v)

1
52

Question 22

22.

A die is thrown twice. What is the probability that 2 will come up atleast once?

(i)

1
3
(ii)

11
36
(iii)

12
37
(iv)

25
36
(v)

5
18

Question 23

23.

A die is thrown 550 times. The number 5 appears on the upper face 106 times. Now the die is thrown at random. What is the probability of getting a 5 ?

(i)

53
275
(ii)

52
275
(iii)

54
275
(iv)

9
46
(v)

222
275

Question 24

24.

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

(i)

37
(ii)

38
(iii)

33
(iv)

36
(v)

35

Question 25

25.

If P(E) =
0.5
, find P(
E
)

(i)

2.5
(ii)

8.5
(iii)

0.5
(iv)

1.5
(v)

7.5

Assignment Key