My 8 GB HP pendrive has 4.87 GB data. However, when I scanned the drive with avast (free version), it showed the amount of data tested as 10.5 GB. No file was found to be infected. I have installed portable application manager with some programs and also contain some compressed files. Is is normal to show the said result or is the pendrive infected? Please advise.
Welcome to the forum. 
You probably have some compressed files on the USB drive.
When avast! scans those files, they are uncompressed (become larger) which is why
there is a discrepancy between the stored files and the scanned size.
Hope that explains it to you.
Thanks a lot, Sir.
Your welcome. (My Dad was Sir) I’m just Bob.