Question

Calculate the temperature which has same numeral value on celsius and Fahrenheit scale.

Answer 1

The formulas for converting between degree Celsius and degree Fahrenheit are:

°F = (°C * 9/5) + 32
°C = (°F - 32) * 5/9

To find the temperature when both are equal, we use an old algebra trick and just set ºF = ºC and solve one of the equations.

°C = (°C * 9/5) + 32
°C - (°C * 9/5) = 32
-4/5 * °C = 32
°C = -32 * 5/4
°C = -40

°F = (°F * 9/5) + 32
°F - (°F * 9/5) = 32
-4/5 * °F = 32
°F = -32 * 5/4
°F = -40

So the temperature when both the Celsius and Fahrenheit scales are the same is -40 degrees.

Answer 2

Formula for Fahrenheit, F = 9/5 C + 32

Formula for Centigrade, C =5/9 (F-32)

Let F = C or C= F

F= C= 5/9(F-32)= (5F-160)/9

9F= 5F - 160

9F - 5F = -160

4F = -160

F = -160/4

F= -40 degree answer in Fahrenheit

C= F= 9/5 C + 32

C = (9C + 160)/5

5C = 9C + 160

5C - 9C = 160

-4C= 160

C=160/-4

C= -40 degree answer in Centigrade

Conclusion: The temperature wherein degrees centigrade is the same in degrees Fahrenheit is -40 degrees .