RIDDLE: Mary has 5 children. ... We can deduce that the answer is “what” because the last sentence of the riddle does not have a question mark. Therefore, we know that it is not asking what the name of the 5th child is, but is instead telling you that the name of the 5th child is “what.”

What is the 5th daughter?

What is the name of the fifth daughter? A: Mary. The first four daughters all have names with the first 4 vowels, so if someone does not think about the question, they may say the name with the fifth vowel, Nunu.

How many daughters did Mr Smith have?

Mr Smith had Four daughters, each daughter had a brother.