Probability

Probability

1. Examples

   • Dice: Two dice are rolled, what is the probability of getting 12 as a sum? Solution: Number of possible outcomes = 6^2 = 36 Number of favorable outcomes = 1 P(E)= 1/36
   • Coin: when a coin is tossed, what would be the probability of appearing head? Solution: total outcomes = 2 favorable outcomes =1 required problem P)e)= 1/2
   • Card: What is the probability of getting an ace from a pack of 52 cards? solution: Number of favorable outcomes = 4 Number of possible outcomes = 52 P(E) = 4/52= 1/13

2. Theoretical Probability

   • 0<P(E)=/< 1
     • What we expect to happen in an experiment
       • Number of trials in P(E) = which the event happened/ Total number of trials

3. Definition

   • Sure or Certain Event: WHen event having probability to occur as 1
   • Complimentary Event: For event E, complement event, P(E) =1-P(E)
   • Elementary event: Event having only one outcome of the experiment

4. Value

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

5. Experimental Probability

   • What actually happens in a experiment
     • Number of outcomes P(E) = favourable of E/Number of all possible outcomes of the experiment