Settle a bet

[LinusKS]

So my friend and I made a 10% swap on a tourny.

I limped into the money and he went out early.

My prize was 50, entry 20, so I say net = $30, his percent = $3.

He says he should get $5.

Who's right?

Please respond, because there's $2 riding on this, and we've agreed to let 2+2 settle it.

Thanks.