Which is sharper, a fixed length focal lens or a zoom lens?

I would guess the fixed length focal lens are...

A zoom lens, even a top quality one has to compromise at most points of it's range, there is usually a "sweet spot" somewhere around the middle where focus is at maximum level, but at wide and tele ends there is a marked fall off in image quality.

Hi,
As an avid photographer, not professional, I own a couple of camera. One is a single lens reflex, Nikon Photomic T, which has auto camera and light settings, or can be used manually... not a digital.
A fixed lens normally will give the sharpest photos, unless of course, you have a good Zoom lens, using it at it's "normal setting".
The more Zoom you use, the less quality you will get.
A good Zoom lens, without Zooming it, is the same as a "fixed lens", and the quality depends on the quality of the lens itself.
A "throw away" camera bought for just taking a few pictures, then turning in the camera and film for developing, doesn't come close to a "quality lens".
I do wish you the best, and the best way is to take some photos, used both a "fixed lens", and then take some with a Zoom lens, zoomed out, and see the quality difference.