Answer:
co-dom: both traits show without either completely masking each other: red flower x white flower = pink offspring.
incomplete: both traits show but dont mask: red x white = red and white flower
simple: one dominant trait masks the recessive trait, red x white (where red is dominant) = primarily red flowers (depending on if the flowers are heterozygous or homozygous there will be a different number of red flowers, with a minimum of 2/4).