It's pretty difficult to answer since we would need to know how you performed overall.
Like, was it the first interview?
If yes, are you confident you performed well in all the other parts? In my opinion, in the first "error", if you mentioned the other sources of revenues within the case, it's fine.
Not considering the business travelers is not a small error (think about NH hotels, they are all business hotels), but it depends on how the error was made.
Example: usually the interviewer shows you a few signs if he/she is not happy with the answer (are you sure? Aren't you missing something here?) or makes faces. Did it happen and you ignored the signals?
Because in that case, it could be worse. In case he/she didn't do anything, they could have written it down and decide to go ahead with you and test you on similar cases in the following steps.
But again, is really difficult to say without having seen the whole interview :)