Packet Tracer Activity: PC2 can't ping PC5 in VLAN20

in CCNA & CCENT
I did this Packet Tracer troubleshooting VLAN activity. Fixed 3 things to make PC1 to be able to ping PC4, and PC3 to be able to ping PC6. But I just can't figure out why PC2 isn't able to ping PC5. HELP!!!
Please delete '.doc' from the file name to run it. Thanks.
Please delete '.doc' from the file name to run it. Thanks.
Comments
With what you told me, I took a look at the interfaces. PC5 is actually on fa0/17, not fa0/18 as marked in the diagram. And fa0/17 belongs to VLAN10, not VLAN20. After I attached PC5 to fa0/18, it worked.
Thanks.