According to a 2007 America's Families and Living Arrangements Census Bureau survey, 52.1 million children lived with both of their parents in the same household, whereas 21.6 million lived with at most one parent in the household. Assume that all U.S. children are included in this survey and that this information is true for the current population. If one child is selected at random, what are the two complementary events and their probabilities?