Yes or no: If the problem you solved before you solved the problem you solved after you solved the problem you solved before you solved this one, was harder than the problem you solved after you solved the problem you solved before you solved this one, was the problem you solved before you solved this one harder than this one?
Solution
Only two problems are referred to here. You can see this by writing something like the diagram below and then tracing the references step by step through the problem backwards.
For example, the last part of the problem refers to "the problem you solved before you solved this one." That is problem numbered 2 in the diagram. Next (working backwards) is "the problem you solved after you solved the problem you solved before you solved this one." This is trickier. Starting with "this one" (#3), we go to "the problem you solved before you solved this one" (#2) and then the whole shebang, "the problem you solved after you solved the problem you solved before you solved this one" takes us back to #3.
You finish the problem. You won't need #'s 1 or 4 or 5. And yes! The problem before was (probably) harder than this problem.