Final answer:
The intersection of the sets A, B, and C is {10}.
Step-by-step explanation:
The intersection of three sets A, B, and C is the set of elements that are common to all three sets. In this case, set A = {4,3, 10}, set B = {3, 6, 10, 15}, and set C = {4, 10, 20}. To find the intersection, we can look for the elements that appear in all three sets. The intersection of A, B, and C is {10}.