Jane Street | Quant Trading Intern | Probability | Phone Screen

Question 1 A client approaches you with the following game: they have a coin with an unknown bias p, where p is drawn uniformly from [0, 1]. They will flip it 10 times. Before any flips, you must quote a two sided market (bid and ask) on the total number of heads. The client sees your quote and chooses to either buy or sell, you don't get to pick. After you quote, the client immediately and eagerly buys your offer. T...