GWD-11-10

Q10:

A certain quantity is measured on two different scales, the R-scale and the S-scale, that are related linearly.  Measurements on the R-scale of 6 and 24 correspond to measurements on the S-scale of 30 and 60, respectively.  What measurement on the R-scale corresponds to a measurement of 100 on the S-scale?

A.     20

B.     36

C.     48

D.     60

E.      84

我的算法是（24-6）/（60-30）=x/100            算出来x=60，可是给的答案是48？

为什么嘞？？