The probability of having offspring that have wrinkled seeds and yellow seed color for the cross RRYY ´ RrYy is A.0 percent. Let's look this cross as two separate crosses for each trait. In the cross RR x Rr, the offspring will be as following: RR (round seeds) and Rr (round seeds). In the cross YY x Yy, the offspring will be as following: YY (yellow seeds) and Yy (yellow seeds). So, none of their offspring will have wrinkled seeds and yellow seeds.