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    

 

Maths by Mr. M. P. Keshari
Subjects Maths (Part-1) by Mr. M. P. Keshari
Chapter 9 Circle
Chapter 10 Tangents to a circle
Chapter 11 Geometrical Construction
Chapter 12 Troigonometry
Chapter 13 Height and Distance
Chapter 14 Mensuration
Chapter 15 Statistics
Chapter 16 Probability
Chapter 17 Co-ordinate Geometry