Revision/test (probability (x)

1) Two dice are rolled. Find the probability of getting a sum 7.

2) A number is chosen at random from the first 11 natural numbers; then the probability that the chosen number is even.

3) An unbiased coin is tossed 3 times in succession, find the probability of getting exactly one head

4) The probability of getting 11 when an ordinary die is thrown twice

5) Three children are selected at random from a group of 3 boys and 2 girls. Write down the sample space of this random experiment.

6) A number is chosen at random from the numbers 1,2,.....,15. Find the probability that the chosen number is

A) even

B) odd

C) multiple of 3.

7) From a pack of 52 cards, 1 card is drawn at random. Find the chance of drawing

A) a spade

B) not spade

8) What is the probability of getting 7 points with the rolling of two dice?

9) What is the probability of picking a spade or an ace not of spade from a pack of 52 cards?

10) A box contains 50 articles of which 4 are defective. Find the probability that an article chosen at random from the box is non defective.

11) A die is thrown. Write down the sample space. What is the probability that either an odd number or a number greater than 4 will turn up ?

12) An unbiased coin is tossed two times. Write down the sample space. Hence find the probability of getting exactly one head.

13) Given that a family of two children has a boy, what is the probability that the other also is a boy

14) It is known that a family has three children and atleast one of these three children is a girl. Find the probability that all the three children are girls.

15) A coin is tossed n times. Find the probability of odd numbers of head.

16) Two dice are rolled. Find the probability of getting a total of 5 points on these dice.

17) In a single cast with 3 dice what is the probability of getting 3 sixes.

18) In a single cast with 3 dice what is the probability of getting different digits.

19) In a single cast with 3 dice what is the probability of getting same digits in two dice and different digit in the other.

20) What is the probability of getting a sum of 8 in a single cast with two dice.

21) What is the probability of getting atleast 8 in a single cast with two dice.

22) In a family there are 4 children. Find the probability that

A) all of them will have different birthdays

B) two of them will have the same birthday

23) What is the probability that a leap year selected at random will contains 53 Mondays? Find also the probability of having 53 Mondays in a year, which is not a leap year.

24) Two fair dice are thrown simultaneously. The two scores are then multiplied together. Calculate the probability that the products is

A) 12

B) even

25) There are 52 cards with each of two boys. Each draws a card at random. What is the probability that

A) both the cards will be king of diamonds

B) both will be diamonds

C) both will be kings

26) If two numbers are selected at random from the numbers 1, 2, 3, 4 determine the probability that their sum is odd when they are selected together.