Final answer:
The intersection of Set R and Set S is {20}.
Step-by-step explanation:
The intersection of two sets, R and S, is formed by taking the elements that are common to both sets. Set R = {10, 15, 20} and Set S = {20, 25}. To find the intersection, we look for elements that are present in both R and S. In this case, the only element that is common to both sets is 20. Therefore, the intersection of R and S, written as R ∩ S, is {20}.