i found a .pka file related to VTP lab sim. However, it looks blank. Without it, it is impossible to solve the question cos i can't build a topology without knowing which PCs belong to which VLAN.
here is the file :
http://packettracer.net/2011/06/13/packettracer-vtp-sim/
the link is that. But, once i open that file on packet tracer it looks blank. So, how am i supposed to build the topology?