Suppose there are two genes that independently assort and determine the color of acorns. The first locus has an allele, G, that codes for the dominant phenotype Grey and the allele, g, that codes for the recessive phenotype of a colored acorn. The second locus has the allele R that codes for a dominant red phenotype and an r that codes for a recessive brown phenotype. The first locus, when dominant, masks the phenotype produced by the second locus and follows a dominant epistasis pattern. Given a heterozygous acorn self-crosses, how many brown acorns would be expected from 320 offspring?