Answer:
0%
Step-by-step explanation:
The question is about a gene coding for flower colour in four o'clock plants. The alleles exhibit incomplete dominance i.e the allele for red color (R) is incompletely dominant over the allele for white color (r), hence, an heterozygous intermediate phenotype, which has a pink color, is produced when both alleles combine i.e. Rr.
A parent with red flowers will possess a genotype: RR while a parent with white flowers will possess a genotype: rr. When both parents are crossed using a punnet square (see attached image), all possible offsprings will possess a pink heterozygous phenotype with genotype Rr.
Therefore, the percentage probability of producing an offspring with genotype: rr is 0% since it is not possible considering the parent's genotypes.