A certain quantity is measured on two different scales, the \(R\)-scale, and the \(S\)-scale, which are related linearly

[Gmat_mission]

A certain quantity is measured on two different scales, the \(R\)-scale, and the \(S\)-scale, which 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

Source: GMAT Prep