Chapter 16: Probability

Exercise - 31

1. (1) A dice is thrown once. Find the probability of getting
   (a) A number greater than 3
   (b) A number less than 5
2. A bag contain 5 black, 7 red and 3 white balls. A ball is drawn from the bag at random. Find the probability that the ball drawn is
   (a) Red
   (b) Black or white
   (c) Not black
3. A bag contains 4 red 5 black and 6 white balls. A ball is drawn from the bag a random. Find the probability that the ball drawn is
   (a) White
   (b) Red
   (c) Not black
   (d) Red or white
4. A card is drawn at random from a pack of 52 playing cards. Find the probability that the card drawn is neither a queen nor a jack.
5. Tickets numbered from 1 to 20 are mixed up together and then a ticket is drawn at random. What is the probability that the ticket has a number which is a multiple of 3 or 7?
6. In a single throw of dice, what is the probability of
   (a) An odd number on one dice and 6 on the other
   (b) A number greater than 4 on each dice
   (c) A total of 11
   (d) Getting same number on either dice.
7. A die is thrown twice. Find the probability of getting
   (a) doublets
   (b) number greater than 5 on one dice.
8. Three coins are tossed simultaneously. Find the probability of getting
   (a) Exactly 2 heads
   (b) No heads
9. In a simultaneous toss of four coins, What is the probability of getting:
   (a) Less than 2 heads?
   (b) Exactly 3 head
   (c) More than 2 heads?
10. Three coins are tossed once. Find the probability of:
    (a) 3 heads
    (b) exactly 2 heads
    (c) at least two heads

Answers

1. 1/2, 2/3,	2. 7/15, 8/15, 2/3	3. 2/5, 4/15, 2/3, 2/3	4. 11/13,
5. 2/5	6. 1/6, 1/9, 1/18, 1/6	7. 1/6, 11/36	8. 3/8, 1/8
9. 5/6, 3/8, 5/16	10. 1/8, 3/8, 1/2