Minisaurs with two recessive genes are gray, heterozygotes are yellow, and dominant homozygotes die at the embryonic stage

Minisaurs with two recessive genes are gray, heterozygotes are yellow, and dominant homozygotes die at the embryonic stage of development.
a) What progeny (in percentage) should be expected when crossing yellow and gray minisaurs?
b) What progeny (in percentage) should be expected when crossing only yellow minisaurs?
c) How many times will there be more yellow minifigures than gray ones?
d) What phenotype splitting can be expected in F1 in the first case?
e) What phenotype splitting can be expected in F1 in the second case?
f) What kind of splitting would be in F1 in the second case, if recessive homozygotes were also nonviable?

Answer: 50 yellow, 50 gray / 66 yellow, 33 gray / 2/1: 1/2: 1/0.