Two thermometers are calibrated,one in degrees Celsius and the other in degrees Fahrenheit.At what temperature is the reading on the thermometer calibrated in degrees Celsius ten times the reading on the other thermometer?
A)-21.8 $\circ$ C
B)-20.0 $\circ$ C
C)-18.8 $\circ$ C
D)-4.00 $\circ$ C
E)-1.88 $\circ$ C

Question

Quizplus · Accepted Answer

Let the temperature in degrees Fahrenheit be x. Then we know that the temperature in degrees Celsius is (5/9)(x-32). We want to find the temperature at which this Celsius reading is 10 times the Fahrenheit reading:

(5/9)(x-32) = 10x
Solving for x, we get x = -4.4 degrees Fahrenheit. Converting this back to Celsius, we get:
(5/9)(-4.4-32) = -18.8 degrees Celsius.
Therefore, choice C is the correct answer.

Two Thermometers Are Calibrated,one in Degrees Celsius and the Other ∘\circ∘

Two Thermometers Are Calibrated,one in Degrees Celsius and the Other $\circ$