# Probability and set language

Probability is all about the chances of things happening.  It is used everyday by everyone even though they might not realise it.

Bob: “You reckon it’s going to rain this avo mate?”

James: “Not sure dude, I’d say fifty – fifty at the moment.”

What James has just done is express what he thinks the probability of it raining that afternoon is.  His statement ‘fifty – fifty’ refers to the chance of it raining and also the chance that it won’t rain.  He reckons there’s a 50% chance that it will rain, but also a 50% chance that it won’t rain.

Another area where probability is very, very important is in the fun world of gambling.  Most people who gamble in casinos either have no idea what the exact probabilities are of them winning, or know that they aren’t good, and are just doing it for fun rather than to earn any money.

Probability is in my opinion the hardest topic in high school maths.  Why is it so hard – two reasons:

·         First up, understanding exactly what a question in probability is asking you to calculate is very, very hard.  Questions can be very ambiguous (have more than one way of being read and interpreted).

·         Getting your head around some of the concepts in probability is also very hard.  It’s best to start with simple examples and build up from there.