Genetics word problem help

In guinea pigs, short hair is dominant and long hair is recessive. A short haired male and a short haired female produce mostly short haired offspring, but a few are long haired. What are the genotypes of the parents?
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This is for homework I did all the other questions but couldn't figure this one out.. please explain how to do it if you can, thanks! :)

Both parents are heterozygous for them to produce a few fully recessive offspring.
S- short hair
s- long hair

Ss x Ss => 1/4 SS, 1/2 SS, 1/4 ss

Easy. If one of the parents was Homozygous, then their progeny would all be short haired.

Both parents are heterozygous.

I suggest you read this:
http://en.wikipedia.org/wiki/Punnett_squ…

Or watch either of these videos:
http://www.youtube.com/watch?v=d4izVAkhM…
http://www.youtube.com/watch?v=D5ymMYcLt…