In general, it is not like a lottery with all winners evenly sharing (most of) the proceeds. Instead, there is a fixed payout, typically around 60% payback. So with 3 digits (1000 combinations), the payout would be $600 for $1 bet.

https://en.wikipedia.org/wiki/Numbers_game

Wouldn't the payout ratio have been known in advance, when the bet was being placed? From what I understand, the "bankers" would set that ratio in advance and pay out of their pockets if necessary.