The Logic Question Almost Everyone Gets Wrong

Jack is looking at Anne, but Anne is looking at George. Jack is married, but George is not. Is a married person looking at an unmarried person? [Possible answers: yes, no, cannot be determined]

(Source: an article in The Guardian by Alex Bellos)

This is the sort of question like the one about the cost of a bat and a ball where a reflexive answer will tend to be wrong. Because Anne's marital status has not been given upfront, as it has with Jack and George, one might immediately suspect that it cannot be determined. But consider that "being married" is an obviously binary predicate. So look at both possibilities: if Anne is married, then a married person (Anne) is looking at an unmarried one (George) and if Anne is unmarried then a married person (Jack) is still nonetheless looking at an unmarried person (Anne). Anne's marital status is irrelevant, so the answer is yes.