That reminds me of a guy who was hired to work with me back at DuPont with a Masters degree in Chemical Engineering that I asked to calculate the actual weight of ferrous chloride in a gram of ferrous chloride heptahydrate (7 extra water molecules). It was a simple calculation, but he kept getting it wrong. I tried to walk him through calculating the total weight minus the water weight but he still couldn’t get it right.
Finally I asked him the percent a quarter was of a dollar. His answer was “4”. I asked him to rethink that and he came back again with the same answer.
I told him he needed to go back and study basic math because he was incorrect.
He told me insistently that he must be right because he had gotten a 99% grade in calculus and that proved he knew what he was talking about.
He got his termination notice the next morning.