Tentang suhu dan termometer

Diketahui
10°C   →  5 cm
  x        → 15 cm
100°C → 25 cm
Ditanya:
x = ———?
Jawab:
(x – 10)/(100 – 10) = (15 – 5)/(25 – 5)
(x – 10)/90 = 10/20
x – 10 = 1/2 x 90
x – 10 = 45
x = 55°c
(Jawab: B)