CBSE Board Practice

Class VI Class VII Class VIII Class IX Class X
CBSE Grade IX - Probability
Question 1
1.
A coin is tossed 100 times and head appears 30 times. If the coin is tossed again, what is the probability of getting a tail?
  • 8
    11
  • 3
    10
  • 4
    5
  • 7
    10
  • 3
    5
Question 2
2.
Which of the following are true?
a)
    • P(E) - P(
    •  

      E
       
       
    • ) = 0
b)
    • P(E) + P(
    •  

      E
       
       
    • ) = 0
c)
    • P(E) + P(not E) = 1
d)
    • P(E) - P(not E) = 0
e)
    • P(E) = 1 - P(
    •  

      E
       
       
    • )
  • {d,a,c}
  • {a,c}
  • {b,e,c}
  • {c,e}
  • {b,e}
Question 3
3.
A survey of 50 men showed that only 40 of them know Telugu. Out of these men, if one is selected at random, what is the probability that the selected man knows Telugu?
  • 4
    5
  • 5
    6
  • 3
    5
  • 1
  • 1
    5
Question 4
4.
Two coins are tossed simultaneously 50 times and it was observed that both heads appeared 35 times. If two coins are tossed simultaneously at random, what is the probability of getting both heads?
  • 3
    5
  • 4
    5
  • 3
    10
  • 8
    11
  • 7
    10
Question 5
5.
There are 80 students in a class room of whom 40 are boys and 40 are girls. From these students, one is choosen at random. What is the probability that the choosen student is a girl ?
  • 3
    4
  • 5
    6
  • 4
    5
  • 1
    2
  • 2
    3
Question 6
6.
Two players Sujatha and Meena play a tennis match. It is known that the probability of Sujatha winning the match is 0.50. What is the probability of Meena winning the match?
  • 3
    4
  • 4
    5
  • 5
    6
  • 2
    3
  • 1
    2
Question 7
7.
    • A die is thrown 295 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
      35
      40
      45
      65
      85
    • If the die is thrown again randomly, find the probability of getting 4 as outcome.
  • 9
    59
  • 10
    59
  • 1
    6
  • 8
    59
  • 50
    59
Question 8
8.
    • 270 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
      81
      90
      99
    • Compute the probability of the family, chosen at random, having 2 girls.
  • 19
    30
  • 1
    3
  • 2
    5
  • 12
    31
  • 11
    30
Question 9
9.
Which of the following are possible values of probability?
a)
0.86
b)
3
9
c)
8
1
d)
5
e)
-2.4
  • {d,b}
  • {c,a}
  • {e,c,a}
  • {d,b,a}
  • {a,b}
Question 10
10.
    • If P(E) =
    • 0.57
    • , find P(
    •  

      E
       
       
    • )
  • 1.43
  • 2.43
  • 7.43
  • 8.43
  • 0.43