Mary’s father has five daughters: Nana, Nene, Nini and Nono. What is the fifth daughter’s name?

How to think about it

1. Notice the pattern in the four names: Nana, Nene, Nini, Nono. Your brain wants to complete the vowel series with Nunu.
2. Before answering, reread the opening. The riddle is about Mary’s father, so Mary is one of his children.
3. Count the daughters named so far: four. The riddle says there are five, so one is missing from the list.
4. The missing daughter has already been named at the start of the sentence. The fifth daughter is Mary.

Why “Mary” is the answer

The question introduces the father through his daughter Mary, which means Mary belongs to the set of five daughters. The four N-names cover the other four, so the fifth is the one person the riddle mentioned before the list began. The pattern of vowels is deliberately placed to pull your attention away from that first word.

Common wrong answers

• Nunu. The vowel pattern suggests it, but the riddle never says the names follow a pattern, and Nunu would make six daughters once you count Mary.