According to www.Ask.com
http://www.ask.com/web?q=How+many+Ha...rc=0&o=0&l=dir

Then there's this;
There are 12 Hasselblad Cameras on the Surface
of the Moon.

http://www.petapixel.com/2011/06/15/...e-of-the-moon/

Did you know that there are 12 Hasselblad
cameras currently sitting on the surface of the
moon ? The cameras that shot those iconic images
of the moon’s surface between 1969 and 1972 were
left there to allow for the 25kg of lunar rock samples
that were brought back instead.

Only the film magazines were brought back.

I wonder why ? Surely they could have been
unloaded in the Lunar Module, so the cameras
could have been left on the moon complete,
hopefully for some future collector to find.