ChhProbability
Whenoneobjectisrandomlyselectedfromnobjects Pselectinganyparticularobj In
P event Nooffavourableequally
likelyoutcomes
Totalno ofequallylikelyoutcomes
In anexhaustiveeventsumofprobabilitiesisibÉaseoÉofthemiscertain tooccur
ofanexperiment Trial
Repeat
Mutuallyexclusive Havenocommonfavourableoutcomessoitsnotpossibleforbotheventstooccur PAAndB 0
Additionlawfor2 mutuallyexclusiveevents P AorB P A P B P AUB PA P B
vennagrams
ofoutcomesfavourable toeventA
Number nA 00 00
AUBAaB AMB AandB
SetofoutcomesnotfavourabletoeventA A
Forany2events AandB P AorB P AUB PA PB P AMB
eventsEither
Independent occurwithoutbeing
can
other
affected occurrenceof
by t.no
Multiplicationlawfarindependent
events
PAAndB PANB PAJXPB
Conditionalprobability Probabilitythatisdependenton aboutaneventatom
someadditionalinformationgiven
AMutuallydependentevents NeitherIanoccurwithoutbeingaffectedbytheoccurrenceoftheother
P BIA P P AIB AMB BNA
p p
P AandB PA XPBIA
As itsconditionalthenfindtotalprobabilitythen probabilityofcondition
If
Whenoneobjectisrandomlyselectedfromnobjects Pselectinganyparticularobj In
P event Nooffavourableequally
likelyoutcomes
Totalno ofequallylikelyoutcomes
In anexhaustiveeventsumofprobabilitiesisibÉaseoÉofthemiscertain tooccur
ofanexperiment Trial
Repeat
Mutuallyexclusive Havenocommonfavourableoutcomessoitsnotpossibleforbotheventstooccur PAAndB 0
Additionlawfor2 mutuallyexclusiveevents P AorB P A P B P AUB PA P B
vennagrams
ofoutcomesfavourable toeventA
Number nA 00 00
AUBAaB AMB AandB
SetofoutcomesnotfavourabletoeventA A
Forany2events AandB P AorB P AUB PA PB P AMB
eventsEither
Independent occurwithoutbeing
can
other
affected occurrenceof
by t.no
Multiplicationlawfarindependent
events
PAAndB PANB PAJXPB
Conditionalprobability Probabilitythatisdependenton aboutaneventatom
someadditionalinformationgiven
AMutuallydependentevents NeitherIanoccurwithoutbeingaffectedbytheoccurrenceoftheother
P BIA P P AIB AMB BNA
p p
P AandB PA XPBIA
As itsconditionalthenfindtotalprobabilitythen probabilityofcondition
If
