CBSE Board Practice

Class VI Class VII Class VIII Class IX Class X
CBSE Grade IX - Probability
Question 1
1.
A die is thrown 60 times. Prime numbers appeared on the upper face 20 times. If a die is thrown at random, what is the probability of getting a prime number?
  • 1
    3
  • 1
    2
  • 2
    3
  • 0
Question 2
2.
    • If P(E) =
    • 0.29
    • , find P(
    •  

      E
       
       
    • )
  • 0.71
  • 7.71
  • 2.71
  • 1.71
  • 8.71
Question 3
3.
Two coins are tossed simultaneously 150 times and it was observed that both tails appeared 60 times. If two coins are tossed simultaneously at random, what is the probability of getting both tails?
  • 2
    5
  • 3
    5
  • 1
    2
  • 1
    5
Question 4
4.
A coin is tossed 70 times and tail appears 40 times. If the coin is tossed again, what is the probability of getting a head?
  • 1
    2
  • 2
    7
  • 4
    7
  • 3
    7
Question 5
5.
A survey of 110 men showed that only 60 of them know Sanskrit. Out of these men, if one is selected at random, what is the probability that the selected man knows Sanskrit?
  • 6
    11
  • 5
    11
  • 7
    11
  • 7
    12
Question 6
6.
Two coins are tossed simultaneously 100 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?
  • 8
    21
  • 3
    10
  • 13
    20
  • 2
    5
  • 7
    20
Question 7
7.
    • The following table shows the blood-groups of 288 students of a class.
    • Blood group
      B
      AB
      O
      A
      Number of students
      45
      54
      90
      99
    • One student of the class is choosen at random. What is the probability that the choosen student has blood group 'AB' ?
  • 4
    17
  • 3
    16
  • 13
    16
  • 1
    4
  • 1
    8
Question 8
8.
    • 216 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
      81
    • Compute the probability of the family, chosen at random, having 2 girls.
  • 3
    8
  • 4
    9
  • 1
    2
  • 1
    4
  • 5
    8
Question 9
9.
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 unsure event is 0
d)
    • The probability of an impossible event is 1
e)
    • The probability of an imposible event can be > 1
  • {c,a}
  • {a,b}
  • {e,c,a}
  • {d,b,a}
  • {d,b}
Question 10
10.
In a lottery, there are 26 prizes and 19 blanks. What is the probability of not getting a prize?
  • 26
    45
  • 10
    23
  • 19
    45
  • 4
    9
  • 2
    5