Three boxes are presented to a contestant. Exactly one box has an expensive gift and the other two are empty. Each box has a declaration imprinted on it. Box 1: 'The gift is not here'. Box 2: 'The gift is not here'. Box 3: 'The gift is in Box 2'. A declaration can be either true or false. Find the least number of true declarations that allows the contestant to logically deduce the gift-box.
Tap an option to check your answer.
Checking your account…
Three boxes are presented to a contestant. Exactly one box has an expensive gift and the other two are empty. Each box has a declaration imprinted on it. Box 1: 'The gift is not here'. Box 2: 'The gift is not here'. Box 3: 'The gift is in Box 2'. A declaration can be either true or false. Find the least number of true declarations that allows the contestant to logically deduce the gift-box. (A) 0 (B) 1 (C) 2 (D) 3
Logic and proof techniques has come up 73 times in 3 exams since 2004.
This question is on Logical reasoning puzzles, part of Logic and proof techniques in Mathematics.
Deduction problems that ask what must follow from a set of constraints.
TestStop has 47 past-paper questions on this subtopic.
Question from the DSE 2021 paper. Solutions are TestStop's own. Not affiliated with or endorsed by any examination authority.