prep 2 43

Kath1985

Q43
Acollegeadmissionsofficer predicts that 20 percent of the students who are accepted will not attend the college. According to this prediction, how many students should be accepted to acheive a planned enrollment of x students?
(A) 1.05x
(B) 1.1x
(C) 1.2x
(D) 1.25x
(E) 1.8x

答案D
見解答寫這樣
"將需接受的學生人數設為A,則0.8A=X, 則可求出A=1.25X"
請問:
明明A和x就是兩個未知數 三個數有兩個是未知數 怎麼能推得出必須錄取1.25x學生呢?

我系大P

是用x去表达A, 你就当做x是已知吧....