Question

while it is a less common way (than probability) of expressing likelihood and does not follow the six rules of probobility, statements of odds are often encountered in gambling contexts. for example, the odds against an event A happening can be expressed as: count of outcomes in which A does not happen / count of outcomes where A happens

This is equivalent to the formula to the formula P(A^C)/P(A). If there are 3:2 odds against a particular horse winning a race, what is the probability that the horse wins?