EduSahara™ Worksheet

Question 1

1.

What is the probability of a sure event?

(i)

0
(ii)

1
(iii)

1
2
(iv)

3
4
(v)

1
4

Question 2

2.

What is the probability of an impossible event?

(i)

1
4
(ii)

1
2
(iii)

3
4
(iv)

1
(v)

0

Question 3

3.

There are 50 students in a class room of whom 30 are boys and 20 are girls. From these students, one is choosen at random. What is the probability that the choosen student is a boy ?

(i)

3
5
(ii)

2
5
(iii)

2
3
(iv)

4
5

Question 4

4.

There are 60 students in a class room of whom 38 are boys and 22 are girls. From these students, one is choosen at random. What is the probability that the choosen student is a girl ?

(i)

12
31
(ii)

11
30
(iii)

1
3
(iv)

2
5
(v)

19
30

Question 5

5.

In a lottery, there are 27 prizes and 16 blanks. What is the probability of getting a prize?

(i)

7
11
(ii)

16
43
(iii)

26
43
(iv)

28
43
(v)

27
43

Question 6

6.

In a lottery, there are 29 prizes and 15 blanks. What is the probability of not getting a prize?

(i)

4
11
(ii)

15
44
(iii)

7
22
(iv)

16
45
(v)

29
44

Question 7

7.

Which of the following are true?

a)	If the probability is too less, it will become negative
b)	The probability of an event that is very likely to happen is 1
c)	If the probability of failing the exam is 0.71, the probability of passing the exam is 0.29
d)	Probability of getting 103 marks out of 100 is 1.03
e)	The probability of an event that cannot happen is unknown

(i)

{c}
(ii)

{b,c}
(iii)

{d,e,c}
(iv)

{a,c}

Question 8

8.

Which of the following experiments have equally likely outcomes?

a)	A ball is hit. It reaches the boundary or not
b)	A man starts his vehicle. It starts or it does not starts
c)	A true/false question is attempted. The answer is either right or wrong
d)	A man throws a die. The number on the top is either 1 or not 1
e)	A baby is born. It is a boy or girl

(i)

{c,e}
(ii)

{b,e,c}
(iii)

{b,e}
(iv)

{d,a,c}
(v)

{a,c}

Question 9

9.

Which of the following are possible values of probability?

a)

7

8

b)

3

c)

0.33

d)

-1.3

e)

7

1

(i)

{d,c,a}
(ii)

{e,b,a}
(iii)

{a,c}
(iv)

{b,a}
(v)

{d,c}

Question 10

10.

If P(E) =
0.17
, find P(
E
)

(i)

7.83
(ii)

2.83
(iii)

1.83
(iv)

0.83
(v)

8.83

Question 11

11.

Which of the following are true?

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

(i)

{b,d}
(ii)

{e,a,c}
(iii)

{c,d}
(iv)

{a,c}
(v)

{b,d,c}

Question 12

12.

Which of the following are true?

a)

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

b)

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

c)

P(E) = 1 - P(
E
)

d)

P(E) - P(
E
) = 0

e)

P(E) + P(
E
) = 0

(i)

{d,c}
(ii)

{a,b}
(iii)

{d,c,b}
(iv)

{b,c}
(v)

{e,a,b}

Question 13

13.

Two players Harini and Geetha play a tennis match. It is known that the probability of Harini winning the match is 0.43. What is the probability of Geetha winning the match?

(i)

29
50
(ii)

43
100
(iii)

58
101
(iv)

57
100
(v)

14
25

Question 14

14.

Fathima and Spoorthi are friends. What is the probability that both will have different birthdays? (ignoring a leap year).

(i)

363
365
(ii)

364
365
(iii)

1
(iv)

1
365
(v)

365
366

Question 15

15.

Saraswathi and Vimala are friends. What is the probability that both will have same birthdays? (ignoring a leap year).

(i)

1
183
(ii)

364
365
(iii)

0
(iv)

2
365
(v)

1
365

Question 16

16.

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)

1
4
(iii)

2
5
(iv)

3
4
(v)

0

Question 17

17.

Suppose a die is thrown on a rectangular region as shown below. What is the probability that it will land inside the circle of diameter 20.00 cm?

(i)

3
7
(ii)

71
126
(iii)

4
9
(iv)

56
127
(v)

55
126

Question 18

18.

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
8
(ii)

1
4
(iii)

0
(iv)

7
8
(v)

2
9

Assignment Key