How many alleles for black fur are in the sample population and what percentage of allele frequencey does that repersent?

20 B alleles for black fur are in the sample population. It represents 40% of allele frequency.

The phenotype ratio depends on the frequency of the allele of the dominant and recessive alleles.
Allele frequency is defined as the number of times an allele occurs in a gene pool compared to the total number of alleles in that pool for the same gene.