In peas, smooth seeds (S) are dominant over dented seeds (s), and yellow seeds (Y) are dominant over green ones (y). A plant with smooth and yellow seeds (P) is of an unknown genotype. A test cross was performed to determine the genotype. The ratios of phenotypes in the F1 generation were as follows: 25% are smooth and yellow, 25% are smooth and green, 25% are dented and yellow, and 25% are dented and green. What is the genotype of P? Show your work.