Can you provide some epistasis practice problems for me to work on?

Epistasis is a genetic concept where one gene masks the effect of another gene. Here is a practice problem for you to work on:

In a hypothetical organism, gene A controls the production of enzyme X, while gene B controls the production of enzyme Y. If enzyme X is necessary for the production of enzyme Y, what would be the phenotypic ratio of offspring from a cross between two individuals who are both heterozygous for gene A and gene B?