prep-39 数学

cindytim

Each employee of Company Z is an employee of either Division X or Division Y, but

not both. If each division has some part-time employees, is the ratio of the number of

full-time employees to the number of part-time employees greater for Division X than

for Company Z?

1). The ratio of the number of full-time employees to the number of part-time employees

is less for Division Y than for Company Z.

2). More than half the full-time employees of Company Z are employees of Division X,

and more than half of the part-time employees of Company Z are employees of Division

Y.

Answer:

Let Xf/Yf is the full time in Division X/Y, and Xp/Yp is part time in X/Y, X,Y, and Z are

number of employees in X, Y, and Z.

X=Xf+Xp

Y=Yf+Yp

Z=X+Y

For 1, Yf/Yp<Zf/Zp, as a compensation, Xf/Xp should be greater than Zf/Zp

For2, More than ?Zf /less than ?of the Zp should be greater than Zf/Zp

Answer is D

不太明白第二个条件满足

a10285

可以这么理解，X、Y、Z是三种溶液，part-time employees 是溶质，full-time是水，Z由X、Y混合而成
（2）可以理解为 X占了一半以上的水，   Y占了一半以上的溶质
  即x浓度<y浓度，而z浓度必然是在X,Y浓度之间，因此可以判断 X, Z的关系~~~~