Mensa Intelligence Test
I dunno how official this is, but the Mensa Intelligence Test has a list of cryptic codes that you have to make out. For example, 24 H in a D = 24 hours in a day. They get harder than that. I got 10/33 14/33 so far. I say so far because my brain is sleepy and I’ll probably come back to it later. Try it out if you want to feel dumb.