Which does John like?

In this case, there are patterns to what John likes. He likes 400, 100, and 2500. We need to see what these things have in common. All three numbers have two zeros in them. We also need to see what John does not like. He does not like 300, 99 and 2400.

Two of these numbers have two zeros in them, so that theory could not be correct. It can be determined that the numbers that Jon likes have two zeros on the end, but there is something else that sets these numbers apart than the numbers that he doesn’t like.

The pattern is that the number that Jon doesn’t like has one hundred or one subtracted from it. So, the next line is that he probably likes 900 but doesn’t like 800.