9.7 Probability

In general:

Probability of an event happening P(E) =		Number of ways it can happen n(E)
		Total number of outcomes n(S)

Example: The probability of rolling a " 6 "with a die.

               Number of ways it can happen: 1 (since there has only 1 face with a "6" on a die)

               Total number of outcomes: 6 ( because there has total 6 faces on a die)

               so we write probability =1/6

Also, we can know the probability from the probability line, and it is always between 0 and 1. When the probability is zero then it's consider an impossible event; for the probability of 1 we called certain event.