Question

In a genetic cross between two flowering plants that are heterozygous for the color trait, red flowers (R) are dominant to white flowers (r). What fraction of the offspring should have red flowers?

Answer 1

Draw a punnet square:
R. r.
R. RR. Rr
r. Rr. rr

Any combo that results in an R results in red flowers.

3/4 offspring have red flowers.