Genetics question.. please help?

It's pretty simple when you're only working with one gene. We know that the alleles sort independently, so we should see 25% of the offspring with a genotype of Cy Cy, 50% with a genotype of Cy cy, and 25% with a genotype of cy cy (you get these ratios by doing a monohybrid cross on a Punnett square). If the female lays 100 eggs, we just apply these ratios to get our expected number of offspring for each phenotype. Twenty five flies (those that are Cy Cy) will die, leaving 75 viable progeny. For part a of the question, we just want to know how many progeny are Cy cy, which will be 50% of ALL progeny, including the dead ones, so 50 flies. For part b, we want to know what percentage of the living flies are zygous recessive, which we get by taking the total number of curly-winged flies (25% of the offspring x 100, or 25) and dividing by the number of living progeny, so 25/75 or 33%.