[問題] GWD 11 - Q10

[kwtluck]

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 =>;-$ 請大家幫忙解題Thanks!!~

[Madi]

原題中提到S和R為線性關係
因此設y=ax+b

30=6a+b
60=24a+b
解聯立方程式可得a=5/3，b=20
將100代入y=5/3x+20式子中
得x=48