it's your problem .. you're not allowed to be bored with itThe problem is designed to think about addition and subtraction of fractions, whilst thinking logically. I'm not a teacher so not used to expressing it in a way to avoid pedants like you. However, my original post did mention the water wouldn't seep to the bottom.
Agree with the second point Tho, the poster who used %age's rounded which led to the wrong answer.
Bored with this now.
filling the bottles back up i.e. to 1.0 every time means you just need to know 1/3 > 1/4 to get a solution... so the only subtraction is 1 - 1/3 = 2/3 ?