The point labeled CYW would be her outcome if she could increase her GPA from a 1.0 to a 2.0 without any additional effort. Obviously, this won't happen either. Could she raise her GPA from a 1.0 to a 2.0 by giving up another 9 hours? In other words, does earning a 2.0 take exactly twice the effort of earning a 1.0? Probably not. It almost certainly takes more than twice the effort. One reason for this is that she would spend the first 9 hours doing those things that would most easily raise her grades. After those are accomplished, the next easiest ways to raise her grades will be more time consuming. The point labeled C, shows where she earns a 2.0. She has to give up 13 hours of leisure, in addition to the 9 hours she gave up to earn a 1.0. It requires 22 hours each week in academic pursuits for her to earn a 2.0, leaving her 78 hours of leisure.
15 Our student is taking 15 hours, so this doesn't mean she shows up for every class, just enough to know when to take the tests, and to learn enough to barely pass.