Understanding Evolution : Personal response Understanding Evolution : Personal response questionquestion

A class of 100 students was tested for the ability to taste phenylthiocarbamide (PTC). It was found that 50 students could taste it very strongly (genotype TT), 20 students could taste it weakly (genotype Tt), and 30 students could not taste PTC at all (genotype tt). What is the frequency of the recessive allele, t, in the population?

a. 0.40b. 0.50c. 0.60d. 0.80