CBSE Class 10 Mathematics Probability Worksheet Set C

Case Study Based Questions

I. Five friends make up their minds to play a game by using a spinner. They put a spinner down on the ground and set around themselves to play. A spinner contains eight regions, numbered through 8, as shown in the figure, the arrow has an equally likely chance of landing on any of the eight regions. If the arrow lands on a line, the result is not counted and the arrow spun again.

Question. How many possible outcomes are in the sample spaces?
(a) 4
(b) 6
(c) 8
(d) 10
Answer : C

Question. What is the probability that the arrow lands on 4?
(a) 1/4
(b) 1/6
(c) 1/2
(d) 1/8
Answer : D

Question. The set of possible outcomes for event A, in which the arrow lands on an even number is
(a) 2, 4, 6, 8
(b) 2, 4, 6, 10
(c) 2, 6, 8, 10
(d) 4, 6, 8, 10
Answer : A

Question. The probability that the arrow lands on an even number is
(a) 1/4
(b) 1/6
(c) 1/8
(d) 1/2
Answer : D

Question. The probability that the arrow will point at any factor of 8 is
(a) 1/2
(b) 1/4
(c) 1/6
(d) 1/8
Answer : A

II. Some boys are playing with numbers. There is a box which contains 90 discs. They are numbered from 1 to 90. The boys are drawing disc one by one from the box at random and want to find the probability of a particular number.

Question. If one disc is drawn at random from the box, the probability that it bears a two-digit number is
(a) 9/10
(b) 8/90
(c) 89/90
(d) 79/90
Answer : A

Question. Then they put the disc into the box and draw another disc at random. They want to know the probability that it bears a perfect square number. So, the probability of perfect square number is
(a) 8/90
(b) 3/10
(c) 1/10
(d) 1/9
Answer : C

Question. They put the disc into the box and another boy draws another disc at random, and wants to know the probability that it bears a number divisible by 5. So the probability is
(a) 2/5
(b) 3/5
(c) 4/5
(d) 1/5
Answer : D

Question. After putting the disc into the box, the next boy draws a disc at random and wants to know the probability that it bears a prime number. The probability is
(a) 5/18
(b) 4/15
(c) 2/15
(d) 13/45
Answer : C

Question. The boys put all the disc together into the box and next boy draws a disc at random and find the probability that the disc bears a number divisible by 7.
(a) 1/15
(b) 2/15
(c) 4/15
(d) 1/5
Answer : B
 

Q.-Two dice are thrown at a time. Find the probability of the following -
(i) these numbers shown are equal;
(ii) the difference of numbers shown is 1. 
Answer : The sample space in a throw of two dice
s = {1, 2, 3, 4, 5, 6} ×{1, 2, 3, 4, 5, 6}.
total no. of cases n (s) = 6 × 6 = 36.
(i) Here E₁ = the event of showing equal number on both dice
= {(1, 1) (2, 2) (3, 3) (4, 4) (5, 5) (6, 6) }
∴ n (E₁ ) = 6
∴ P (E₁) =n(E₁ )/n(s) =6/36 =1/6
(ii) Here E2 = the event of showing numbers whose difference is 1.
= {(1, 2) (2, 1) (2, 3) (3, 2) (3, 4) (4, 3)  (4, 5) (5, 4) (5, 6) (6, 5)}
∴  n (E₂) = 10
∴ p (E₂) = n(E₂)/n(s) =10/36= 5/18

 

Please click the below link to access CBSE Class 10 Mathematics Probability Worksheet Set C