As far as I know, there are two ways that you can do this.
1) If you cannot access your previous course, you can go into your course settings for your new course, and choose the Import Course Content option. You will then select your previous course and select the entire course or just the quiz files.
2) If you can access the previous course, you can use a recently added feature called "Copy to." You need to located the quiz, and then press the menu button (the three dots that appear to the right side of it), and select "Copy to." You will then enter the name of the course you want to copy to. Word of advice - make sure you know the SIS ID of the course you want to copy it to and enter the SIS ID as that will be the fastest way to find the course.