Answer:
the length is one
Step-by-step explanation:
Put all the white balls in one box and the red ball in the other so you have a 50% chance of winning if you put 1 red ball and a white now you have a 25% chance cause you have a 50% chance in choosing the right box then you have to chose the right ball which would be 50%
Go to desmos.com and type in these equations
