MATHS (PROBABILITY)

DEFINITION OF VARIOUS TERMS

 1. Random experiment: An experiment is said to be random if all possible outcomes of the experiment are known but the exact outcome can not be pericted in advance.

  2. Sample space : The set of all possible outcomes of an experiment is known as sample space and it is usally denoted by S.The sample space of tossing a coin is S ={H,T}and the sample space of tossing two coins at a time is  S= {HT,TH,TT,HH} and the sample space of rolling a die is S ={1,2,3,4,5,6}.and  n(s) represent the number of outcomes of a sample space inS.when a die is rolled twice, then n(s)=6power 2 = 36.Each outcomes of sample space is called Sample point. There are two types of sample spaces namely discrete and continus

DisCrete - when elements are countable.

Continuous - when elements are not countable.

3. TRAIL AND EVENT:To Perform an experiment is known as trial and possible outcomes of the experiment is called event .for example rolling a dice or tossing a coin any number of times is trial and turning up head or tail or occurrence of numbers 1,2,3,4,5,6 are events .so every subset of a sample space is an event.

TYPES OF EVENT

Simple event: An event is said to be simple if it contains only one elememt in sample space.

Compound eveny: An event is said to be a compound event it  having more than one element in sample space.

Eqally likely event or equally probable event:Events are said to be equally likely if there is no reason for an event to occur in preference to any other event .It means events are said to be equally likely when each event is equally likely to occur as any other.