It depends on the course topic, your background, your learning style, and the particular assignments in a given week. In general, you can expect each course to require 15-18 hours per week. Some courses will take less time, while for others you might need to spend 25 hours on a particularly challenging programming assignment.
Please note that 15 hours per week per course is only an estimated average. In reality, these courses could take a little less or a lot more time than estimated based on your prior education or work experience. Not only that, one course can vary week to week: one course could take 10 hours one week and way more in the next!
A good thought exercise before the semester starts is to map out the extra time you typically have in your week and whether you can dedicate 15 hours of that time to your class. What if it was more than 15? Think critically about what would happen if you have a challenging assignment that took you 20-25 hours to complete. Be aware that some of our students spend this much time every week for one course.