Question

A person taking a reading of the temperature in a freezer in Celsius makes two mistakes: first omitting the negative sign and then thinking the temperature is Fahrenheit. That is, the person reads –x°C as x°F. Oddly enough, the result is the correct Fahrenheit temperature. What is the original Celsius reading? Round your answer to three significant figures.

a) -18.5°C
b) -32.8°C
c) -45.2°C
d) -57.9°C

Answer 1

The original Celsius reading is -18.5°C. To convert from Celsius to Fahrenheit, we use the formula F = (1.8 * C) + 32.

Step-by-step explanation:

In this case, we need to find the original Celsius reading when the result is the correct Fahrenheit temperature after omitting the negative sign and thinking it is Fahrenheit.

Let's represent the original Celsius reading as -x°C. When we omit the negative sign, it becomes x°F. Using the conversion formula, we have: x = (1.8 * -x) + 32. Solving this equation, we find that the original Celsius reading is -18.5°C. Therefore, option a) is the correct answer.