Term 2 Week 7

We continue our study of probability by giving absolutely impossible and absolutely certain events a number value:

P(certain) = 1
P(impossible) = 0

We also note that probabilities are 'complementary', that is the probability of something happening added to the probability that it won't happen is always 1.

Eg The probability of rolling a '5' is 1/6 and the probability of not rolling a '5' is 5/6. Adding these together we get the probability of either rolling a '5' or not rolling a '5' is 1.

Knowing this we can calculate the probability of some events very simply:

Eg If we know the probability of winning a lottery is 1/1000000, then we can subract that number from 1 and work out that the probability of not winning the lottery is 999999/1000000.

The Probability Assignment 2 is here

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