I have a new Canon MP480 printer/scanner. I have a 43 KB document that can not be scan into my PC, but it can be scan into my flash drive. The scanned pdf file became 1.53 MB and too large to be attach to my online job application. What happen? How can I get the pdf file back to 43 KB or under 1 MB?

Set the scanner to do black and white with a bit depth of 1 if there are no grays. You can scan at 600 dpi and then have certain software try to do character recognition and downsample. The full version of Acrobat will. You should not need more than 300 dpi for a final output.

You could TRY scanning as a jpg and use the free program IrfanView - Official Homepage - one of the most popular viewers worldwide to downsample. With all the plug-ins installed, it will convert the .jpg to .pdf. I just never tried it.