Internal Memory Miscalculation and Deleted Photos are still in memory

[exo]

I've got two major problem with my Xperia P
1. The phone show total memory is 11.25 G sth, but when I sum the memory of app, downloads, image n video, audio, and free space is only 5.8 G sth! So where is the rest of my memory go?
2. I have deleted photos from my phone, but when I connect my phone to PC n import the photo n video in, I see the pictures n videos that I have deleted before too. Why the files are still in my memory? Is this the cause to problem 1?
Please kindly help me

[Uliwooly · Accepted solution]

Try this

settings > apps > menu > sort them by size > open the top apps > clear cache

[_alexdon_]

Do what uli told you,also try to delete LOST.DIR folder in internal storage.Go to settings-apps-all-media storage,clear data,restart the phone.