About Tier 1 - Element
Focused around one main idea or observation.
Difficulty describes the challenge, not the solver. It is a Society guide rather than a formal academic level.
The tier is a Society guide to the amount of reasoning, technical work and insight a problem is expected to require. Your experience may vary depending on the topic and your background.
A Pair in the Dark
Combinatorics / Pigeonhole Principle - 3 min
A drawer contains socks in exactly three colours, with at least four socks of each colour. You draw socks without seeing their colours. Any two socks of the same colour make a matching pair. What is the smallest number you must take to guarantee a matching pair, however unlucky the selection?
Assumptions
A matching pair means any two socks of the same colour. No assumption about the likelihood of a selection is needed.
More Options for A Pair in the Dark
Collection question · Revision 1 · ID: socks-in-the-dark