求教 OG12-31

EvaCheng

是在Diagnostic Test里的逻辑题,
Cheever College offers several online courses via remote computer connection, in addition to traditional classroom-based courses. A study of student performance at Cheever found that, overall, the average student grade for online courses matched that for classroom-based courses. In this calculation of the average grade, course withdrawals were weighted as equivalent to a course failure, and the rate of withdrawal was much lower for students enrolled in classroom-based courses than for students enrolled in online courses.


If the statements above are true, which of the following must also be true of Cheeer College?
A, Among students who did not withdraw, students enrolled in online courses got higher grades, on average, than students enrolled in classroom-based courses.
B, The number of students enrolled per course at the start of the school term is much higher, on average, for the online courses than for the classroom-based courses.
C, There are no students who take both an online and a classroom-based course in the same school term.
D, Among Cheever College students with the best grades, a significant majority take online, rather than classroom-based, courses.
E, Courses offered online tend to deal with subject matter that is less challenging than that of classroom-based courses.
我的理解是: 这学校有两种课程,在线和教室的. 对于学生表现的调查,在线学生的成绩和教室里学生的成绩是差不多的. 在计算成绩的时候,课程的取消和课程的失败同样处理(这句话我不是很理解,是什么意思??),教室里学生取消的比率要比在线学生取消的比率低.
为什么后来课程取消的比率和学生成绩又有关系呢? 有没有可能教室里的学生和在线的学生水平都差不多所以计算出来的成绩比较接近.
这题我完全没有思路...混乱 希望N人解释一下~ 谢谢!
答案是A

amandafly

真正理解题目了,其实答案很简单.

ruiqijjkkl

这题怎么没有人解释？小生冒昧顶上去~

wangsiwei

这是一个数学题。
（on-line 完成课程的总分数＋withdraw的总分数 ＋failure的总分数）／on-line学生总数＝＝＝
（class 完成课程的总分数＋withdraw的总分数 ＋failure的总分数）／class学生总数
withdraw = failure
题目说了，class withdraw的rate <on-line withdraw的rate
推一推，就得到A了

wangsiwei

涉及到数字，百分比什么的，尤其是比较长，比较混乱的题，考虑考虑是不是数学题。

ahasusanna

不懂，withdraw了怎么还有分数呢，不是算0吗