A thermometer reading -7°C is brought into a room kept at 23°C. Half a minute later the thermometer reads 8°C. What is the temperature reading of the thermometer after a further two and a half minutes?
A) 12.5°C
B) 32.5°C
C) 22.5°C
D) 15.5°C
E) 28.5°C

Question

Quizplus · Accepted Answer

The temperature of the thermometer increases rapidly at first and then more slowly as it approaches the room temperature. Given the initial jump from -7°C to 8°C in half a minute, we can infer a rapid warming, but as it gets closer to the room temperature of 23°C, the rate of increase will slow down. It won't reach or exceed the room temperature in the given time, making 22.5°C a reasonable estimate of its progress towards equilibrium with the room temperature.

A Thermometer Reading -7°C Is Brought into a Room Kept