Btw. An iq-test measures the intrinsic abilities of your brain.
A proper iq test would be even solveable by people who neither can read nor do maths.
E.g. you could take some amazonian native who dont know anything about modern society and test them.
You dont need any language or math skills - it is not about knowledge, but about pattern recognition and logical thinking.
Also low iq people wont be able to be an einstein but high iq people have the chance to be an einstein.
This is more accurate in theory of how it's supposed to be. Though when I was a kid and a professional gave me an IQ test, there are parts that deal with general knowledge and how well the person has picked up on it. Things that you pick up in culture and society. Intelligent people are more curious than less intelligent people, so there are some general knowledge things that come across throughout life, but the less curious person will not pick up due to never concerning themselves with more than superficial simple things.