Probability

Probability

1. Examples

   • Dice: Two dice are rolled what is the probability of getting 12 as a sum ?
     • Solution; No, of possible outcome= 36 No. of favourable outcome= 1 i.e(6,6)O(E) = 1/36
   • Card: What is the probability of getting an ace from a pack of 52 cards ?
     • Solution; No. of favourable outcome= 4 No. of possible outcome= 52, P(E)= 4/52= 1/13
   • Coin: When a coin is tossed what would be the probability of apperearing head ?
     • Solution; Total outcome= 2 i.e(H,T) Favourable outcome= 1 Probability P(E)= 1/2

2. Definitions

   • Complementary Event: For event E, complement event P(e)+1-P(E)
   • Elementary Event: Event having only one outcome of the experiment.
   • Sure or Certain Event: When event having probability to occur as 1.
   • Impossible Event: Probability of an event is equal to 0

3. Value

   • Sum of Probability of all elementary events is 1. For events A,B,C;P(A)+P(C) =1

4. Theoretical Probability

   • 0<P(E)<1P(E) = Number of trials in which the events happened/ Total no. of Trials.

5. Experimental Probability

   • What actually happens is an experiment : P(E)=Number of outcome favourable to E/No. of all possible outcome of the experiment.