Question

A centigrade and a Fahrenheit thermometer one dipped in boiling water. The water temperature is lowered until the Fahrenheit thermometer registers 140°. What is the fall in temperatures as registered by the centigrade thermometer ? 

(A) 30° 

(B) 40° 

(C) 60° 

(D) 80°

Answer 1

The correct option is (B) 40°.

Explanation:

We know {(F – 32) / (180)} = {C / (100)} 

Given F = 140 

∴ {(140 – 32) / (180)} = {C / (100)} 

∴ C = 60°C 

∵ Temperature of boiling water = 100°C 

∴ required falls is 100 – 60 = 40°C