请教 GMATPrep 一题

Each perosn attending a fund-raising party for a certian club was charged the same admission fee, How many people attended the party?

1) If the admission fee had been $0.75 less and 100 more people had attended, the club would have received the same amount in admission fees.

2) If If the admission fee had been $1.50 more and 100 fewer people had attended, the club would have received the same amount in admission fees.

答案: C

我设admission fee 为 x; 人数为 y

(x-0.75)(y+100)=(x+1.5)(x-100)

可是我解不出着个方程啊? 请问NN帮我看一下哈, 十分感谢!!

设AD FEE为X，person Y

(X-0.75)(Y+100)=XY   100X-0.75Y-75=0

(X+1.5)(Y-100)=XY    -100X+1.5Y-150=0

两式相加，可求出Y=300，代入Y，得出X=3

Hi,

You don't have to get the specific answers for X, Y. Once you see

(X-0.75)(Y+100)=XY   100X-0.75Y-75=0

                           +

(X+1.5)(Y-100)=XY    -100X+1.5Y-150=0

you can guess x,y must be some numbers.

这种题是不能去算的