[問題]GDW 12-23

[blacklilu]

The average (arithmetic mean) score on a test taken by 10 students was x. If the average score for 5 of the students was 8, what was the average score, in terms of x, for the remaining 5 students who took the test?

A. 2x - 8
B. x - 4
C. 8 - 2x
D. 16 - x
E. 8 - X/2

Ans : A
...借問式子是怎麼出來滴？ @@@

[huacy]

十個人的總分 = 10x
其中五個人的總分 = 5*8
剩下五人的平均 = (10x-40)/5 = 2x - 8