The Problem: I often develop practice questions for the courses that I teach. However, I've often found it frustrating having to maintain two versions of what is essentially the same document. One version contains only the questions. Another version contains questions and answers. It inevitably happens that practice questions go through a number of iterations as little errors are identified. However, each error that is identified needs to be changed in both the Question Copy and the Question and Answer Copy. If you're not careful, it's easy enough to get the two versions out of sync.
A Solution: In Microsoft Word you can use hidden text for answers. Thus, answer text is hidden in one version and not hidden in the other version. However, it's still a single document. Thus, any changes only need to be made in one document. The student version can then be printed as a PDF from the one source document.
Text can be hidden by highlighting the text and going to the font setting an selecting "hidden".
A better strategy involving styles:
A better strategy involves the use of styles in Word. Define a style called "Answers". Apply this style to all content involving answer text. Thus, if you want to show the Answer Text instead of hiding it, you only need to change one option in the style.
Showing and Printing Hidden Text:
If you want to see hidden text normally, press control + shift + 8 (or press the little paragraph icon). If you want to print a PDF copy that shows the hidden text, go to: print - options - hidden text.
Figure: Text is hidden
Figure: Hidden text is shown after pressing control+shift+8