Maths by Mr. M. P. Keshari

**Exercise - 31 **

- (1) A dice is thrown once. Find the probability of getting

(a) A number greater than 3

(b) A number less than 5 - 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 - 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 - 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.
- 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?
- 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. - A die is thrown twice. Find the probability of getting

(a) doublets

(b) number greater than 5 on one dice. - Three coins are tossed simultaneously. Find the probability of getting

(a) Exactly 2 heads

(b) No heads - 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? - 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 |