If you are starting with $10, 30% of that is $3
If you are starting with $10, 30% of that is $3 If you bet that and you win, now you have $13, so you can bet 30% of that which is $3.9. But on the first round where you wagered $3, and you lost, now you only have $7, and 30% of that $2.1, so …