Fruit machines (or slot machines or one-armed bandits as they are sometimes known) are common place in most pubs and are also found in amusement arcades and casinos. Playing them is a form of gambling and as such it is illegal for anyone under the age of 18 to use them. Fruit machines work in a fairly simple way, although they have become much more complex over the past decade with the introduction of computer chips into their mechanism. Older style fruit machines would work purely on the basis of probability in terms of how much money they would pay out. Modern machines are usually set to pay out a certain percentage of any money that is put into them (usually between 75% and 80%). These machines are therefore much more likely to pay out if they have had a lot of money put into them but not payed out recently. For the questions that follow, we are only going to look at the older probability based fruit machines.

More information about how fruit machines work can be found at money.howstuffworks.com/slot-machine.htm