About 30% of people do not recognize the bitter taste of phenyl-thio-carbamate (PTC). Inability to taste it is due to a recessive allele denoted by allele a. In other words, AA and Aa are normal individuals who can recognize the bitter taste while an aa individual cannot. The tasting allele A is dominant over the non-tasting allele a. Let p be the frequency of allele A and q be the frequency of allele a. Given that the frequency of genotype aa is 0.30 and the population is in Hardy-Weinberg equilibrium,
(1) What is the frequency of the non-tasting allele, i. e., what is the q value?
(2) Among the people who can recognize the bitter taste, what is the probability of carriers for the non-tasting allele? Note that the probability of carrier is not the frequency of heterozygote, although carriers are heterozygous.