For that to be mathematically correct, if we consider the underestimate case where Bill Gates and Mark Zuckerberg are the only billionaire dropouts currently al

For that to be mathematically correct, if we consider the underestimate case where Bill Gates and Mark Zuckerberg are the only billionaire dropouts currently alive, that would require 200 billion total college dropouts to be currently alive. Out of the 8 billion total people on Earth. Forbes did a study (of sorts) that estimated 44 billionaires of the 362 they had listed were dropouts. That suggests a need to have 4.4 trillion dropouts. Order of magnitude, it's somewhere around a million times more common for a college dropout to become a billionaire than your claim.