Answer:
A.Put each person's name on a separate piece of paper in a bag. Randomly draw the winning name; and D.Roll a number cube. If it lands on an even number, Roddy wins. If it lands on an odd number, Scott wins.
Explanation:
In order for it to be a fair decision, both boys have to have an equal chance of being selected.
For choice A, drawing their names from a bag, both names are equally likely to be chosen; that makes this fair.
For choice B, there is 1 way to get both heads when flipping a coin. There are 2 ways to get heads and tails when flipping a coin. This gives Scott a greater chance, so this is not fair.
For choice C, there are 2 ways to get a 1 or a 2. There are 4 ways to get anything else. This gives Scott a greater chance, so this is not fair.
For choice D, there are 3 even numbers and 3 odd numbers. Both boys have an equal chance, so this is fair.