I’ve been trying to write little arbitrage puzzles. I’m hoping to make them accessible to kids. Here’s one I’m working on now.
It might rain on April 15th. Then again, it might not.
Your first friend agrees to make a bet. If it rains, you get $10. If it doesn’t, you have to pay your friend $5.
You have a second friend who wants the opposite bet. If it rains, you pay your friend $5. If it doesn’t, they’ll pay you $10.
What do you do, and why?
My take on a solution in the comments.