When creating a new test you can either allow us to automatically pick questions for you or you can create an empty test and choose the questions yourself.
Accessing Library
After you have created a test, open the test and head over to Questions section from the sidebar.
Once there, click New Question dropdown and select Add From Library.
Picking a Question
You can either pick a question from our list of questions or you can pick from your previous tests if you are trying to make a similar new test.
Our questions are categorized according to their difficulty. Here we are viewing the Easy ones. You can click a task to read it in detail or click Pick Task to add it to your test.
Close the library after you have added all the questions you need.
Note: You might want to change the Time Limit of the test as you see fit after this.