Quizzes are not available when Tasks has been enabled for a course.
Tasks have their own Quiz which is a collection of tasks
There are two types of quiz: practice (formative) and assessed (summative or real-time assessments). One practice quiz from each course can be turned into a knowledge check quiz if required.
Quizzes are a special type of unit and are initially created in the Content area by selecting the cog wheel and then Add quiz, as shown below.
Give it a name as you would when adding a normal unit, and then select the cog wheel and select Preview/Edit.
This will take you to the following page. Select Insert quiz.
This will bring up a the following dialog box.
Quizzes may be assessed or practice quizzes. The default, shown above, is assessed. This can be toggled by selecting either the Assessed or the Practice button. Below is the setting for a practice quiz.
If you select a practice quiz, additional options are added:
Quizzes are created from a specially formatted spreadsheet. The most up-to-date template, example and notes can be downloaded from this dialog box, as shown below.
The quiz template or example can then be modified to suit your needs and uploaded. Download and review Notes for details.