- Simple Probability:
Probability in general is defined as the ratio between numbers of favourable or desired outcomes to the numbers of outcomes of the experiment. E.g. if an unbiased coin is tossed then the possible outcomes are head (H) or tail (T) so the probability of getting a head is the ratio between number of favourable outcome which is Head (H) in this case to the number of possible outcomes i.e. ½ or .5
- Conditional Probability:
Conditional Probability is the probability of the outcome of an even when one event has already occurred e.g. when a dice is rolled twice what is the probability that the sum of the two dice will be at least 10 given that first one is already 5.
There are 6 outcomes when the first one can be 5 and they are [(5, 1), (5, 2), (5, 3), (5, 4), (5, 5) and (5, 6)]. Out of these 6 outcomes in 2 cases the sum is 10 or more and they are [(5, 5) and (5, 6)]. Hence the probability of getting the sum of two rolls of a dice to be at least 10 when the first one is already 5 is (2/6) or 1/3 or .333.
- Subjective Probability:
Subjective Probability does not involve any mathematical calculation and depends on a person’s judgement on a particular outcome from his/her past experiences. This is a sort of intuitive process.