Subject: what kind of dominant recessive cross produces an 8 :1phenotype ratio

We are doing punnet squares. I do understand this but I do not understand how 
to guess what the parents were in an odd ratio like 8 to one. I have 8 green 
plants and 1 albino plant. I am then asked to guess what the parents plants 
were that made up these and to keep in mind the 3 to one ratio. I have tried 
all types of combinations but none of them add up to 8 to 1 ratios. I would 
appreciate any type of help.
thanks
Tina

Re: what kind of dominant recessive cross produces an 8 :1phenotype ratio