show/hide this revision's text 1 [made Community Wiki]

Sometimes math problems crop up in high school competitions that are secretly linear algebra problems in disguise. For instance, #6 of USAMO 2008 (http://amc.maa.org/a-activities/a7-problems/USAMO-IMO/q-usamo/-pdf/usamo2008.pdf) can be approached via linear algebra over $\mathbb{F}_2$.