If there are 100 individuals in a population and 20 are homozygous for b, 60 are heterozygous, and 20 are homozygous for b, what is the allele frequency of b?

One b should be capitalized to specify for dominant and recessive alleles. luckily dominant and recessive have the same frequency here.

to count each allele b, multiply 2 by homozygous (for each allele) and add 1 for every heterozygous. Then divide by total number of alleles 200.

2 (20) + 60 = 100

100/200 = 0.5