Arts (English Medium) कक्षा ११ - CBSE Question Bank Solutions

Which of the following can not be valid assignment of probabilities for outcomes of sample space S = {ω_1, ω_2,ω_3,ω_4,ω_5,ω_6,ω₇}

A die is thrown, find the probability of following events:

1. A prime number will appear,
2. A number greater than or equal to 3 will appear,
3. A number less than or equal to one will appear,
4. A number more than 6 will appear,
5. A number less than 6 will appear.

A card is selected from a pack of 52 cards.

1. How many points are there in the sample space?
2. Calculate the probability that the card is an ace of spades.
3. Calculate the probability that the card is
   
   1. an ace
   2. black card.

A fair coin with 1 marked on one face and 6 on the other and a fair die are both tossed. Find the probability that the sum of numbers that turn up is (i) 3 (ii) 12

There are four men and six women on the city council. If one council member is selected for a committee at random, how likely is it that it is a woman?

A fair coin is tossed four times, and a person win Re 1 for each head and lose Rs 1.50 for each tail that turns up.

From the sample space calculate how many different amounts of money you can have after four tosses and the probability of having each of these amounts.

Three coins are tossed once. Find the probability of getting

1. 3 heads
2. 2 heads
3. at least 2 heads
4. at most 2 heads
5. no head
6. 3 tails
7. exactly two tails
8. no tail
9. atmost two tails.

In a lottery, person chooses six different natural numbers at random from 1 to 20, and if these six numbers match with the six numbers already fixed by the lottery committee, he wins the prize. What is the probability of winning the prize in the game? [Hint: order of the numbers is not important.]

Check whether the following probabilities P(A) and P(B) are consistently defined

P(A) = 0.5, P(B) = 0.7, P(A ∩ B) = 0.6

Check whether the following probabilities P(A) and P(B) are consistently defined

P(A) = 0.5, P(B) = 0.4, P(A ∪ B) = 0.8

Fill in the blank in following table:

Fill in the blank in following table:

Fill in the blank in following table:

A box contains 10 red marbles, 20 blue marbles and 30 green marbles. 5 marbles are drawn from the box, what is the probability that all will be blue?

4 cards are drawn from a well-shuffled deck of 52 cards. What is the probability of obtaining 3 diamonds and one spade?

From the employees of a company, 5 persons are selected to represent them in the managing committee of the company. Particulars of five persons are as follows:

A person is selected at random from this group to act as a spokesperson. What is the probability that the spokesperson will be either male or over 35 years?

If 4-digit numbers greater than 5,000 are randomly formed from the digits 0, 1, 3, 5, and 7, what is the probability of forming a number divisible by 5 when, the digits are repeated?

The number lock of a suitcase has 4 wheels, each labelled with ten digits i.e., from 0 to 9. The lock opens with a sequence of four digits with no repeats. What is the probability of a person getting the right sequence to open the suitcase?

Find the mean and standard deviation using short-cut method.