[neurotrace]

"100% increase" != "increase by a factor of 1".

You seem to be stuck on the translation here. These are two different phrases with different meanings. Yes, they both refer to increases. Yes, they both can be interpreted as multiplications on the original term. No, they are not the same. You found exactly one case which does not use the same verbage and specifically points to percentages. I don't know how else to say that different phrases in English carry different meanings. You can't just say "a factor of X" is equivalent to "X00%". This just is not understood to be true. Even the GMAT and GRE present questions in this way with the understanding that "a factor of X" means to multiply by X.

I'm not going to continue to explain this to you. There's really nothing more to be said. If you attempt to solve problems presented in the format of "increased by a factor of X" such that X is not presented as a percentage, you will be marked as incorrect more often than not.

I'm not even explicitly arguing for a populism argument. I'm stating that the problem is presented in a different format than you are claiming it to be.