in a game of musical chairs, the person playing music has been advised to stop playing the music at any time within 1 minute after she starts playing. What is the probability that the music will stop within the first 20 seconds after starting?

Cards numbered from 11 to 60 are kept in a box. If a card is drawn at random from the box, find the probability that the number on the drawn cards is

(i) an odd number

(ii) a perfect square number

(iii) divisible by 5

(iv) a prime number less than 20

The king, queen and jack of clubs are removed from a deck of 52 playing cards and the remaining cards are shuffled. A card is drawn from the remaining cards. Find the probability of getting a card of (i) heart (ii) queen

(iii) clubs.

Two dice, one blue and one grey, are thrown at the same time. Complete the following table:

From the above table a student argues that there are 11 possible outcomes 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 and 12. Therefore, each of them has a probability . Do you agree with this argument?

Fill in the blanks:

(i) Probability of a sure event is ………. .

(ii) Probability of an impossible event is ………….. .

(iii) The probability of an event (other than sure and impossible event) lies between ……….. .

(iv) Every elementary event associated to a random experiment has ………. Probability.

(v) Probability of an event A+ Probability of event ‘not A’ = ………….. .

(vi) Sum of the probabilities of each outcome in an experiment is …………. .

Cards marked with numbers 13, 14, 15, …, 60 are placed in a box and mixed thoroughly. One card is drawn at random from the box. Find the probability that number on the card drawn is

(i) divisible by 5

(ii) a number is a perfect square

A group consists of 12 persons, of which 3 are extremely patient, other 6 are extremely honest and rest are extremely kind. A person from the group is selected at random. Assuming that each person is equally likely to be selected, find the probability of selecting a person who is (i) extremely patient (ii) extremely kind or honest. Which of the above you prefer more.

A box contains 100 red cards, 200 yellow cards and 50 blue cards. If a card is drawn at random from the box, then find the probability that it will be (i) a blue card (ii) not a yellow card (iii) neither yellow nor a blue card

A number is selected at random from first 50 natural numbers. Find the probability that it is a multiple of 3 and 4.

Examine each of the following statements and comment:

(i) If two coins are tossed at the same time, there are 3 possible outcomes – two heads, two tails, or one of each. Therefore, for each outcome, the probability of occurrence is 1/3.

(ii) If a die is thrown once, there are two possible outcomes – an odd number or an even number. Therefore, the probability of obtaining an odd number is � and the probability of obtaining an even number is 1/2.

Two dice are thrown simultaneously. What is the probability that:

(i) 5 will not come up on either of them?

(ii) 5 will come up on at least one?

(iii) 5 will come up at both dice?