CBSE Class 9 Mathematics Probability VBQs

Question. 1500 families with 2 children were selected randomly, and the following data were recorded—

No. of girls in a family     2         1        0

No. of families               800    500     200

(a) Compute the probability of a family having 2 girls.

(b) What value is promoted by this data ?

Answer: (a)  800/1500 = 8/15    

       (b) Promotion to girl child

Question. On the occassion of Independence Day celebration out of 1200 students, 900 students took part in this celebration.

(a) Evaluate the probability that the students participated in the celebration.

(b) What values are represented through this activity ?

Answer: (a) 900/1200 = 3/4

         (b) Love for Nation

Question. Sita says that in word MADAM, the probability of letter M is equal to that letter A. Is she right? What value represents in it ?

Answer: (a)   P(M) = P(A) = 2/ 5

(b) Truth value

Question. In 1000 families 750 families have 1 child and rest of families have two children. Find the probability of having (a) 1 child and (b) two children What value represents from this ?

Answer: (a)  750 / 1000 or 3/4

    (b) 250 /1000 or  1/4

    (c) (i) Population control

         (ii) Small family is a happy family

Question. In a colony, 920 out of 1000 people visited Radha Krishan Temple on the occassion of Janamashtmi. Find the probability of people not visited the temple. What value represents in this ?

Answer: (a)  80/1000 or 2/25

    (b) Spiritual value

Question. In a school, 100 students took part in Van Mahotsava and helped each other in planting the tree.

Name of plants      Rose      Mari gold      Chameli     Jasmine

No. of plants          32           28                16            24

Find the probability of planting

(a) Rose (b) Jasmine

What value represents here ?

Answer: (a) 32/100 or 8/25

    (b)  24/100 or  6/25

    (c) (i) Environmental protection

         (ii) Co-operation

Question. Mohan earns Rs. 30,000 in a month. He spends Rs. 25,000 on his needs. What is the probability of his saving ? What value is depicted from it ?

Answer: (a)  5000/30000 or  1/6

   (b) Habit of saving

Question. In a town out of 1000 persons, 998 are literate. Calculate the probability that a selected person is

(a) Literate (b) Illiterate

What value do this data represent ?

Answer: (a)  998/1000 or  499/500

   (b)  2/1000 or  1/500

   (c) Literacy rate is high in cities.

Question. The blood groups of 15 students of class IX are recorded as follows— A, B, O, O, AB, O, A, O, B, A, O, B, A, O, O, AB

Find the probability of blood group—

(a) O

(b) A

(c) What value do you draw from this activity ?

Answer: (a) 7/15

  (b) 4/15

  (c) (i) Habit of donation

       (ii) Social work

Question. On Lajpat Nagar crossing, out of 100 people, 9 people jumped traffic light. Find the probability of people not jumping traffic light. What value is depicted from this ?

Answer: (a) 91/100

    (b) Society becomes aware to avoid accidents and save precious life.

Please refer to attached file for CBSE Class 9 VBQs Probability