# NCERT Class 10 Mathematics Formula CBSE Board Sample Problems Part 9

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## Probability

S.no | Terms | Description |

1 | Empirical probability | It is a probability of event which is calculated based on experiments Empirical Probability Example: A coin is tossed 1000 times; we get 499 times head and 501 times tail, So empirical or experimental probability of getting head is calculated as Empirical probability depends on experiment and different will get different values based on the |

2 | Important point about events | If the event A, B, C covers the entire possible outcome in the experiment. Then, |

3 | Impossible event | The probability of an event (U) which is impossible to occur is 0. Such an event is called an impossible event P (U)=0 |

4 | Sure or certain event | The probability of an event (X) which is sure (or certain) to occur is 1. Such an event is called a sure event or a certain event P(X) =1 |

5 | Probability of any event | Probability of any event can be as |

S.no | Terms | Description |

1 | Theoretical probability | The theoretical probability or the classical probability of the event is defined as Probability P(E) = |

2 | Elementary events | An event having only one outcome of the experiment is called an elementary event. “The sum of the probabilities of all the elementary events of an experiment is 1.” I.e. If we three elementary event A,B,C in the experiment ,then P(A)+P(B) +P(C)=1 |

3 | Complementar y events | The event, representing ‘not A’, is called the complement of the event A. We also say that A and A are complementary events. Also |

4 | Sure or certain event | The probability of an event (X) which is sure (or certain) to occur is 1. Such an event is called a sure event or a certain event P(X) =1 |

5 | Probability of any event | Probability of any event can be as |