What is the answer for the two blank lines? (_+_)

The answer for the two blank lines (_+_) is (CO2 + H2O)

25% or 1/4 of the offspring would have red flowers, 50% or 1/2 of the offspring would have pink flowers, and 25% or 1/4 of the offspring would have white flowers. i crossed rr and rr which are the pink-flowered genotypes to find these ratios.