/sci/ - Science & Math

You're at a game show

You just won 100k and got to the bonus round where you get to bet your prize money in a gimmicky game of chance

The host explains OP's boxes setup. You can bet however much money you want on a box, and if that box contains two golden balls you get 3x the money back

You don't really give a shit, so you put 5k on a box as a token bet

The host spins a fair three-sided die to pick a random box. It lands on a different box than the one you picked

The host walks up to the box the die indicated, sticks his hand inside without looking, and takes out a silver ball

He then offers you to change your bet on the box you initially chose - you may increase or decrease it however you like, but you may not switch box

Also at that point you remember that your great great grand aunt died yesterday and left you 4m so the "100k is a unique opportunity to me"-factor doesn't apply to you. You only care about maximizing your expected winnings

What do you do?