@alisonkiddle@mathstodon.xyz my solution: I note that those are one in 2^10 and one in 6^4 respectively, so it's whether 2^10 is greater or less than 6^4. While I do know 2^10 from memory, I don't know 6^4 and I've got a little bit of a cold and would rather not work it out. But I can divide both by 2^4, to get 2^6 and 3^4, and I know those! Is 64 greater than or less than 81? It's less than! So 2^10 is less than 6^4 and 1/2^10 is greater than 1/6^4. So flipping 10 heads in a row is more likely. Which wasn't what I expected!