Answer :
The percent of population which is heterozyous is 32.5%
Explanation:The homozygous allele "A" is 20% and the other homozygous allele is" a "that is 45%The heterozygus allele is" Aa"This comes from the monohybrid cross in Punnet's square.That will have "Aa"one dominant allele and one recessive allele in the ratio of 1:1:1:1 and the percentage is 10% of" A" and 22.5% of "a",that is 32.5%