In humans freckles are dominant to no freckles. Trey has no freckles and his wife anna grace has freckles, but her dad doesn't. They want to know what percentage of their kids will look like Trey.

50%

Explanation:

Lets denote the freckle allele as "F" and the no freckle allele as "f"

Freckles are dominant to no freckles. Grace has freckles, meaning she must have one "freckle" allele (either FF or Ff). Her dad does not, meaning he has two "no freckle" alleles (ff). Grace has to have inherited one allele of her two alleles from her father, meaning she has to be heterozygous (Ff).

Trey has no freckles, meaning he must be ff. Therefore, the cross of their genotypes would be Ff x ff. The punnett square below shows the outcomes:

F f f Ff fff Ff ff

Half of their kids will have freckles (Ff), and half will not (ff), meaning 50% of their possible kids would look like Trey