Dialogue fits the situation?

Hi. Let's say there are five items, a pencil, a pen, an eraser, a cap and a pencil case, on the desk, and they're supposedly from five students but not sure as to who put what. It is also supposed that one or more students have put one or more items but don't know who they are. Is this dialogue okay as to what might have been said betweeen the two? Thank you in advance for your help.

A: Is this yours?
B; No, it isn't.
A: Then which is yours?
B: Mine are the pencil and eraser.