There’s a popular problem circulating this last day or two, having appeared in Singapore’s Math Olympiad.  As someone who grew up doing extracurricular math competitions, it was cool to see one getting so much attention, even if it was incorrectly claimed in some places to be a problem from a normal elementary school math test.  I’m sure there are a million websites explaining solutions by now, but here’s my version as requested by a friend who wanted to see what I meant when I said that I found a solution by drawing a graph. 🙂
Continue reading Cheryl’s birthday problem →