By default, the correct-answer percentage a user needs to pass a quiz is 70% and the option for users to see the correct answer after an unsuccessful attempt is enabled.
To apply the same settings on all your quizzes:
Sign in to your account as an Administrator.
Open the top-left menu.
Select App Control (1).
On the left-side panel click Learning management (2).
Move to the Quizzes - Test mode defaults section (3).
There, you will find the following three options:
Enforce test score pass percentage: set the quizzes required passing score (in correct-answers percentage)
Show correct answer after an unsuccessful answer attempt: choose whether or not the user is shown the correct answer after an unsuccessful attempt
Randomize the order of the answers
Enable the choices you want and click Save changes.
If you want to edit the settings of a specific set click on this article.