Solution

35704

First name
Rushil Patel
School
Whitgift School
Country
Age
14

There are an infinte number of sets. If there is one even and one odd number pair it is a fair game. You can make an infinite number of pairs this way.

Ball 1,2 Sum, EO
1+2 3 Odd
2+2 4 Even
1+1 2 Even
2+1 3 Odd

Odd chance: 1/2
Even chance: 1/2

Fair game

Ball 1,2 EO
O+E O
E+E E
O+O E
E+O O

Odd chance: 1/2
Even chance: 1/2

Fair game