I had a look at it. Here are some points that you need to consider.
1. Since your using VLANs every where, you need to define sub-interface on the FastEthernet ports of all routers.
2. The switch ports connected to those router ports should also be set to trunk mode.
3. Some PCs are not using the correct subnet mask and gateway.
4. The switches are all on VTP server mode. Only one switch per switching segment should be set to server mode, the rest should be client mode. Still, if you don't do this one, the network will work. but it's not practical to all on server mode since you need to update all switched manually for VLAN changes.
I fixed only the LEFT side of the network, the side behind the "Jurong Industrial" Router. Those PCs on the left can now ping each other. I'll leave the rest to you . Here is the half-fixed file: