Flower diameter in sunflowers is a quantitative trait. Each…

Flower diameter in sunflowers is a quantitative trait. Each upper case allele provides a fixed amount of cm additional in diameter. Each lower case provides a different fixed amount of cm additional in diameter. A plant with 8-cm flowers and aabb genotype is crossed to a plant with 16-cm flowers and a AABB. What is the probability of of getting a 12cm flower in F1?