taotao10-10

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

Answer: c

请教NN，这道题是什么意思？我看不懂啊。