... your comment that they paid $8.33 for the room was a trivial reponse to Charles' post (it would have been inferred at the time he stated that the total room charge was $25.) At no time is their actual room charge at issue - the issue is how much they paid (ie: $9 each). As far as they knew, they had each paid $9 and it all went toward the room. Your post simply divided the room charge by 3 (as a statement) and left it hanging without restating the rest of Charles' post and dividing everything else by 3.

I would infer that the point you are making would end with the question "where did each of their 33-cents go?"