The key is that the students who bet with you know what to eat for breakfast today. If there is, they will only guess one of the other three, that is, the probability of winning is 1/3, the probability of losing is 2/3, and the probability of losing is twice that of winning.

So don't lose money or make money.

If you don't know what to eat for breakfast today, the probability of success is 1/4, the probability of failure is 3/4, and the probability of failure is 3 times that of success.

Then you make a profit.