We are making a cup of coffee and want the temperature to be

We are making a cup of coffee and want the temperature to be just right, so we measure the temperature with both Fahrenheit and Celsius thermometers. The Fahrenheit meter registers 110 degrees Fahrenheit, but you prefer to it to be slightly hotter at 119 degrees Fahrenheit, so we heat it up a little. How much will the Celsius thermometer increase when we make this change?

Solution

initital fahrenheit thermometer reading = 110 degree F

fahrenheit to celcius conversion
C/5 = (F-32)/9
C/5 = (110-32)/9
C/5 = 8.66667
C = 43.33
Thus, initital celsius thermometer reading = 43.33 degree C

Now, the Fahrenheit thermometer reading is changed to 119 degree F
Calculating new celsius reading
C/5 = (F-32)/9
C/5 = (119-32)/9
C/5 = 9.6667
C = 48.33
New celsius thermoemeter reading = 48.33 degree C

Therefore, When fahrenheit thermometer is increased by 9 degree F,
celsius thermometer is increased by 5 degree C