Final answer:
If a person with freckles (Ff) mates with a person without freckles (ff), there is a 50% probability of having a child with freckles.
Step-by-step explanation:
If a person with freckles (Ff) mates with a person without freckles (ff), the probability of having a child with freckles can be determined using a Punnett square. In this case, the Ff parent can produce two types of gametes: F and f, while the ff parent can only produce f gametes. When these gametes combine, there is a 50% chance of getting an Ff genotype and a 50% chance of getting an ff genotype. Therefore, the probability of having a child with freckles is 50%.