Give a fraction with its value in between 2/5 and 1/2.
(Note: the denominator cannot be greater than 20)
This is an open-ended question for primary (elementary) school, which ought to be easy because there are many possible answers and you just need to supply one that meets the requirements. However, most people are used to closed-ended questions, which have only one correct answer. This is what prompted a parent to pose this question on a parent-support forum on Facebook.