You have adopted a gray mouse, which you know is a wild type phenotype. When crossed with a white mouse, your gray mouse has a first litter of 3 gray mice and 2 white mice. In the second litter, you observe 3 gray mice and 4 white mice. What is the probable genotype of your gray mouse

Assuming the white phenotype is recessive. white: gg
I think the gray mouse is Gg because the offspring were pretty equally distributed in terms of color. See the punnet square below.
g g
G| Gg Gg
g| gg gg

If the Gray phenotype is recessive, then gray: ww but only if white is Ww because its about 50% chance for both.