Hi Ann, Although each noun is in its singular form, we have to consider both parents ("parents" is a plural noun) as the word "and" is used to join them together in the sentence. Other examples: 1. What (are) Sam and his brother doing? 2. How (are) Sam and his brother coping in the new company? 3. Why (are) Mom and Dad arguing? Hope this helps.

"Mummy and Daddy are at home." Using the same logic: "Where are Mummy and Daddy?"