A gambler bets half the money in his pocket on the toss of a coin, winning an equal amount for a head and losing his money if the result is a tail. After 2n plays he has won exactly n times. Has he more money than he started with?
You have two bags, four red balls and four white balls. You must put all the balls in the bags although you are allowed to have one bag empty. How should you distribute the balls between the two bags so as to make the probability of choosing a red ball as small as possible and what will the probability be in that case?
To win on a scratch card you have to uncover three numbers that add up to more than fifteen. What is the probability of winning a prize?
What about drawing a sample space of the possibilties.
Try different numbers of each ribbon.
What would happen if you had ribbons of three different colours?