“There are only 10 types of people in the world: those who understand binary and those who don’t.”    — Unknown.Figure it out yet?“10” in binary numerals equals “2” in decimal numerals, so when you read the sentence, pronounce “10” as “two.”In all fairness, a number should have a subscript when its base differs from ten. In this case, it should be written 10#2. But that wouldn’t make for much of a joke then, would it?