Practice variation 3 of 3
Pigeonhole principle — Two colours pigeonhole
Your question
To guarantee at least red marbles when drawing from a bag that only has red and blue, in the worst case you may first take red and all the blue. If there are only two colours and you want of one colour, the minimal guaranteeing monochromatic is
This practice question was inspired by Question 3 in the 2024 NSW HSC Mathematics Extension 1 examination, © NESA. It is an original TestMum variation that practises the same mathematical idea, not an official NESA question.
Before you check
- Have you stated every choice or assumption?
- Can another student follow each line?
- Did you verify the final result independently?