Theorem of total probability - class-XI

A comprehensive quiz covering probability fundamentals including sample spaces, events, and the theorem of total probability for class-XI students.

18 Questions Published

Questions

Question 1 Multiple Choice (Single Answer)

There are 50 marbles of 3 colors: blue yellow and black The probability of picking up a blue marble is 3/10 and that of picking up a yellow marble is 1/2 The probability of picking up a black ball is 

  1. 1/5
  2. 1/10
  3. 1/4
  4. 4/5
Question 2 Multiple Choice (Single Answer)

Difference between sample space and subset of sample space is considered as 

  1. numerical complementary events.
  2. equal compulsory events.
  3. complementary events.
  4. compulsory events.
Question 3 Multiple Choice (Single Answer)

We draw two cards from a deck of shuffled cards without replacement. Find the probability of getting the second card a queen.

  1. $\dfrac{1}{13}$
  2. $\dfrac{2}{13}$
  3. $\dfrac{5}{13}$
  4. None of these
Question 4 Multiple Choice (Single Answer)

Which of the following is true regarding law of total probability?

  1. It is a fundamental rule relating marginal probabilities to conditional probabilities.
  2. It expresses the total probability of an outcome which can be realized via several distinct events
  3. Both are correct
  4. None of these
Question 5 Multiple Choice (Single Answer)

I have three bags that each contain $100$ marbles- Bag $1$ has $75$ red and $25$ blue marbles, Bag $2$ has $60$ red and $40$ blue marbles, Bag $3$ has $45$ red and $55$ blue marbles. I choose one of the bags at random and then pick a marble from the chosen bag, also at random. What is the probability that the chosen marble is red?

  1. $0.60$
  2. $0.40$
  3. $0.50$
  4. None of these
Question 6 Multiple Choice (Single Answer)

For a random experiment, all possible outcomes are called

  1. numerical space.
  2. event space.
  3. sample space.
  4. both b and c.
Question 7 Multiple Choice (Single Answer)

Tossing a coin is an example of .........

  1. Infinite discrete sample space
  2. Finite sample space
  3. Continuous sample space
  4. None of these
Question 8 Multiple Choice (Single Answer)

The term law of total probability is sometimes taken to mean the ____

  1. Law of total expectation
  2. Law of alternatives
  3. Law of variance
  4. None of these
Question 9 Multiple Choice (Single Answer)

The events $E _1, E _2, ........$ represents the partition of the sample space $S$, if they are:

  1. pairwise disjoint
  2. exhaustive
  3. have non-zero probabilities
  4. All are correct
Question 10 Multiple Choice (Single Answer)

The experiment is to repeatedly toss a coin until first tail shows up. Identify the type of the sample space.

  1. Finite sample space
  2. Continuous sample space
  3. Infinite discrete sample space
  4. None of these
Question 11 Multiple Choice (Single Answer)

The experiment is to randomly select a human and measure his or her length. Identify the type of the sample space.

  1. Finite sample space
  2. Continuous sample space
  3. Infinite discrete sample space
  4. None of these
Question 12 Multiple Choice (Single Answer)

Given a circle of radius $R$, the experiment is to randomly select a chord in that circle. Identify the type of the sample space.

  1. Finite sample space
  2. Continuous sample space
  3. Infinite discrete sample space
  4. None of these
Question 13 Multiple Choice (Single Answer)

Sample space for experiment in which a dice is rolled is

  1. $4$
  2. $8$
  3. $12$
  4. None of these
Question 14 Multiple Choice (Single Answer)

Choosing a birthdate is an example of .........

  1. Infinite discrete sample space
  2. Finite sample space
  3. Continuous sample space
  4. None of these
Question 15 Multiple Choice (Single Answer)

Sample space for experiment in which two coins are tossed is

  1. $8$
  2. $4$
  3. $2$
  4. None of these
Question 16 Multiple Choice (Single Answer)

In a construction job, following are some probabilities given:
Probability that there will be strike is $0.65$, probability that the job will be completed on time if there is no strike is $0.80$, probability that the job will be completed on time if there is strike is $0.32$. Determine probability that the construction job will get complete on time.

  1. $0.438$
  2. $0.538$
  3. $0.488$
  4. None of these
Question 17 Multiple Choice (Single Answer)

There are three boxes, each containing a different number of light bulbs. The first box has 10 bulbs, of which four are dead, the second has six bulbs, of which one is dead, and the third box has eight bulbs of which three are dead. What is the probability of a dead bulb being selected when a bulb is chosen at random from one of the three boxes?

  1. $\dfrac{115}{330}$
  2. $\dfrac{113}{360}$
  3. $\dfrac{113}{330}$
  4. None of these
Question 18 Multiple Choice (Single Answer)

Suppose that two factories supply light bulbs to the market. Factory X's bulbs work for over $5000$ hours in $99%$ of cases, whereas factory Y's bulbs work for over $5000$ hours in $95%$ of cases. It is known that factory X supplies $60%$ of the total bulbs available. What is the chance that a purchased bulb will work for longer than $5000$ hours?

  1. $\dfrac{876}{1000}$
  2. $\dfrac{544}{1000}$
  3. $\dfrac{974}{1000}$
  4. None of these