EduSahara™ Worksheet

Question 1

1.

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

(i)

1
2
(ii)

1
(iii)

1
4
(iv)

4
5
(v)

3
4

Question 2

2.

234 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

72

99

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

(i)

7
26
(ii)

8
27
(iii)

4
13
(iv)

3
13
(v)

19
26

Question 3

3.

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 girl ?

(i)

19
32
(ii)

13
32
(iii)

5
8
(iv)

20
33
(v)

9
16

Question 4

4.

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

(i)

0
(ii)

1
2
(iii)

2
5
(iv)

3
4
(v)

1
4

Question 5

5.

A survey of 150 men showed that only 95 of them know Hindi. Out of these men, if one is selected at random, what is the probability that the selected man knows Hindi?

(i)

2
3
(ii)

19
30
(iii)

3
5
(iv)

20
31
(v)

11
30

Question 6

6.

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

(i)

2
3
(ii)

1
2
(iii)

5
6
(iv)

3
4
(v)

4
5

Question 7

7.

In a lottery, there are 13 prizes and 17 blanks. What is the probability of getting a prize?

(i)

7
15
(ii)

14
31
(iii)

17
30
(iv)

2
5
(v)

13
30

Question 8

8.

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

(i)

1
3
(ii)

1
6
(iii)

0
(iv)

5
6
(v)

2
7

Question 9

9.

A bag contains 52 red balls, 60 white balls, 20 yellow balls and 24 gray balls. One ball is drawn at random from the bag. Find the probability that the ball drawn is not white.

(i)

9
13
(ii)

5
13
(iii)

7
13
(iv)

9
14
(v)

8
13

Question 10

10.

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 less then 21?

(i)

2
5
(ii)

5
14
(iii)

2
7
(iv)

9
14
(v)

3
7

Question 11

11.

A missing helicopter is reported to have crashed somewhere in the rectangular region shown in fig. What is the probability that it crashed inside the shaded region as shown in the figure?

(i)

1
4
(ii)

7
8
(iii)

0
(iv)

1
8
(v)

2
9

Question 12

12.

Two coins are tossed simultaneously 80 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)

2
3
(ii)

1
2
(iii)

4
5
(iv)

5
6
(v)

3
4

Question 13

13.

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

(i)

5
6
(ii)

4
5
(iii)

3
4
(iv)

2
3
(v)

1
2

Question 14

14.

A die is thrown twice. What is the probability that 6 will come up atleast once?

(i)

25
36
(ii)

1
3
(iii)

5
18
(iv)

11
36
(v)

12
37

Question 15

15.

52 cards are numbered 1,2,3,....52 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)

37
52
(ii)

4
13
(iii)

15
52
(iv)

16
53
(v)

7
26

Question 16

16.

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 0.67, the probability of passing the exam is 0.33
d)	The probability of an event that cannot happen is unknown
e)	Probability of getting 101 marks out of 100 is 1.01

(i)

{a,c}
(ii)

{b,c}
(iii)

{c}
(iv)

{d,e,c}

Question 17

17.

A box contains 80 discs which are numbered from 1 to 80. If one disc is drawn at random from the box, find the probability that it bears a number divisible by 5.

(i)

4
5
(ii)

2
5
(iii)

0
(iv)

1
3
(v)

1
5

Question 18

18.

A carton consist of 88 shirts of which 74 are good, 12 have minor defects and 2 have major defects. Mahender, a trader, will only accept the shirts which are good, but Kajal, 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 Mahender?

(i)

38
45
(ii)

37
44
(iii)

19
22
(iv)

9
11
(v)

7
44

Question 19

19.

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

(i)

0
(ii)

2
13
(iii)

1
12
(iv)

11
12
(v)

1
6

Question 20

20.

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?

(i)

3
13
(ii)

1
26
(iii)

1
13
(iv)

1
52
(v)

1
4

Question 21

21.

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

(i)

1
(ii)

1
3
(iii)

2
3
(iv)

3
4

Question 22

22.

Which of the following are true?

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

(i)

{c,a}
(ii)

{d,b,a}
(iii)

{d,b}
(iv)

{a,b}
(v)

{e,c,a}

Question 23

23.

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

(i)

1
4
(ii)

1
2
(iii)

1
(iv)

3
4
(v)

4
5

Question 24

24.

A coin is tossed 50 times and head appears 25 times. If the coin is tossed again, what is the probability of getting a tail?

(i)

1
2
(ii)

3
4
(iii)

5
6
(iv)

2
3
(v)

4
5

Question 25

25.

What is the probability of a sure event?

(i)

3
4
(ii)

0
(iii)

1
(iv)

1
2
(v)

1
4

Assignment Key