Answer:
540
Step-by-step explanation:
In this case, the mutation rate from the allele black fur to the allele gray fur decreases by 10 percent per generation, while the original number of black fur alleles is 600.
Percentage of 10% of 600 = (10 x 600) / 100 = 60 alleles
In consequence, the number of black alleles in the next generation will be >>> 600 - 60 = 540 alleles