9.18+Probability+Trees

media type="custom" key="7387893" width="70" height="70" align="right" ﻿ ﻿ Probability trees are maths-friendly and eco-friendly... I can:
 * Calculate probabilities from a probability tree



To find out the probability of something, all you have to do is multiply the number of outcomes from the the first and second branch(of the probability tree) together. For example, the number of possible outcomes on the first branch is 2 (H and T), now multiply that with the number of possible outcomes on the second branch (H and T (2), __NOT__ H and T and H and T (4)). And that is how to work out probabilities using nothing but your brain...and a tree :) some people think probability trees are hard or boring (or both) and they should just get over it and be thankful that they don't have to use a probability tree like this one...
 * Calculate expected number