Questions completed, some one please double check !? TIA

A dominant allele, T, codes for the ability to taste the compound phenylthiocarbamide (PTC). People who are homozygous for the recessive allele, t, are unable to taste PTC. In a genetics class of 125 students, 28 cannot taste the PTC. How many students would you expect to be heterozygous for the tasting gene?

I answered : 0.83

A dominant allele, T, codes for the ability to taste the compound phenylthiocarbamide (PTC). People who are homozygous for the recessive allele, t, are unable to taste PTC. In a genetics class of 105 students, and 9 cannot taste the PTC. Calculate the expected frequencies of the t allele in the student population. 1 mark
Your Answer:
0.09

A dominant allele, T, codes for the ability to taste the compound phenylthiocarbamide (PTC). People who are homozygous for the recessive allele, t, are unable to taste PTC. In a genetics class of 165 students, and 19 cannot taste the PTC. Calculate the expected frequencies of the T allele in the student population. 1 mark
Your Answer: 0.88

In a randomly mating population of mice, 2 out of every  100 mice born have white fur, a recessive trait. Calculate the heterozygous frequency for the population.  1 mark
Your Answer:
0.24