I always hate it when slutty girls who I've either not seen in more than semster/year, or girls I've never seen at all, come up to me and my friends in the caff and ask for some spare change.
Are you sure they're slutty and not skanky? It's okay to be annoyed by the slutty ones if you want, but the skanky chicks should be respected. As a general rule of thumb, sluts come from relatively well off households (there are of course exceptions), and tend to have access to money (and other things)if they need it, but enjoy using sex as a way to manipulate people into giving them what they awnt. Skanks, on the other hand, while generally similar in appearence to sluts, tend to come from poor/dysfunctional homes and have promiscuous sex just for the fun of having sex (or if you want to get into the psychological motives of things, in order to keep people from getting into a "deep" relationship with them which could risk exposing their dysfunctions and other issues), rather than to manipulate. There are other differences as well, some of which are quite subtle, but suffice to say that skanks deserve your sympathy and respect, if not for the dysfunctional nature of their existence then for the fact that they will give you "no strings attached" sex if they like you...so I certainly hope that these people asking you for change really are sluts and not skanks...just something for you to think about.