If 2 brown mice are mated and 30 of the offspring are brown and 9 are white what is the phenotype?

The phenotype refers to the observable characteristics of the offspring. In this case, since the majority of the offspring (30 out of 39) are brown, the phenotype of the majority is brown. The presence of 9 white mice suggests that the brown mice are likely heterozygous, carrying a recessive allele for white fur, while the white mice display the recessive phenotype.