if B and b are the two alleles , B + b = 1 and B ^2 +2 Bb + b ^2 = 1.
If 16% of mice are homozygous black , B ^ 2 =0 .16, meaning B = 0 .4 and b = 1 - 0. 4 = 0 .6 .
Answer = Notice how you don't even need to know that 24% of the mice are heterozygous .