CBSE Board Practice

CBSE Grade IX - Probability
Question 1
1.
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 baby is born. It is a boy or girl
c)
A man throws a die. The number on the top is either 6 or not 6
d)
A man starts his vehicle. It starts or it does not starts
e)
A ball is hit. It reaches the boundary or not
  • {a,b}
  • {d,b,a}
  • {e,c,a}
  • {c,a}
  • {d,b}
Question 2
2.
A die is thrown 70 times. Prime numbers appeared on the upper face 25 times. If a die is thrown at random, what is the probability of getting a prime number?
  • 2

    7
  • 3

    7
  • 5

    14
  • 2

    5
  • 9

    14
Question 3
3.
A coin is tossed 100 times and head appears 65 times. If the coin is tossed again, what is the probability of getting a tail?
  • 7

    20
  • 8

    21
  • 2

    5
  • 13

    20
  • 3

    10
Question 4
4.
    • On a particular day, at a crossing in a city, the various types of 135 vehicles going past during a time-interval were observed as under:
    • Type of Vehicle
      Four-wheeler
      Two-wheeler
      Three-wheeler
      Frequency
      30
      50
      55
    • Out of these vehicles, if one is choosen at random, what is the probability that the choosen vehicle is a 'Three-wheeler' ?
  • 10

    27
  • 11

    27
  • 3

    7
  • 16

    27
  • 4

    9
Question 5
5.
In a lottery, there are 28 prizes and 15 blanks. What is the probability of not getting a prize?
  • 16

    43
  • 4

    11
  • 28

    43
  • 14

    43
  • 15

    43
Question 6
6.
In a lottery, there are 26 prizes and 19 blanks. What is the probability of getting a prize?
  • 19

    45
  • 26

    45
  • 27

    46
  • 5

    9
  • 3

    5
Question 7
7.
    • If P(E) =
    • 0.2
    • , find P(
    •  


      E
       
       
    • )
  • 0.8
  • 2.8
  • 8.8
  • 1.8
  • 7.8
Question 8
8.
There are 58 students in a class room of whom 36 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 ?
  • 12

    29
  • 2

    5
  • 10

    29
  • 18

    29
  • 11

    29
Question 9
9.
There are 42 students in a class room of whom 22 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 ?
  • 10

    21
  • 6

    11
  • 4

    7
  • 11

    21
Question 10
10.
A die is thrown 300 times. The number 3 appears on the upper face 60 times. Now the die is thrown at random. What is the probability of getting a 3 ?
  • 4

    5
  • 2

    5
  • 0
  • 1

    5
  • 1

    3