It is possible to embed WeBWorK exercises into a PreTeXt document. It is possible to build an HTML version in which readers can answer these exercises and find out if their answer is correct or incorrect. However, results of WeBWorK exercises cannot yet be recorded to your gradebook. Because WeBWorK content belongs inside an <exercise>, you can include WeBWorK exercises in any of the elements that can contain an <exercise> such as a <worksheet> and <reading-questions>. There's some configuration required use WeBWorK. Please see Chapter 7 and Chapter 36 for more details. There is a WeBWorK Sample Chapter available elsewhere, with copious examples and output in multiple formats.