That must be a really big underdog you are betting on -)
That means if you are betting only $5, its still 30 to 1 payment, so $5 would win 30 to 1 and that would $150 dollars. So thats 30 to 1 odds payout on your money. That means that a $100 bet would win $3000 dollars. If i bet 5 dollars on a +3000, how much would i win?