Show me the working out to: 48 week course, 12 hours a week.
must attend 80% of the class to pass. how many days can one have off?

If you would like to know how many days, weeks can one have off, you can calculate this using the following steps:

48 week course * 12 hours a week = 48 * 12 = 576 hours in total

80% of the class = 80% of 576 hours = 80% * 576 = 80/100 * 576 = 460.8 hours

576 hours in total - 460.8 hours = 576 - 460.8 = 115.2 hours

115.2 hours / 12 hours a week = 115.2 / 12 = 9.6 weeks

You can have 9.6 weeks off.