Answer: The probability of producing offspring with genotype Rr is 100%.
Explanation-
Round seed is a dominant trait ( depicted by dominant R allele) whereas wrinkled seed is a recessive trait ( depicted by recessive allele r).
According to the law of segregation of genes, the alleles will separate from one another during gamete formation.
Pea plant with round seeds will produce two gametes that is R and R whereas plant with wrinkled seeds will produce r and r gametes.
When the parents are crossed, they will result in the offspring with genotype Rr ( that will exhibit round seed phenotype).
Refer punnett square.