1978 AHSME Problems/Problem 22
The following four statements, and only these are found on a card:
(Assume each statement is either true or false.) Among them the number of false statements is exactly
There can be at most one true statement on the card, eliminating and . If there are true on the card, statement ("On this card exactly four statements are false") will be correct, causing a contradiction. Therefore, the answer is , since are false and only the third statement ("On this card exactly three statements are false") is correct.