A linear thermometer X is designed such that it reads 20∘X at the melting point of ice and 120∘X at the boiling point of water, both at standard atmospheric pressure.
a. (i) Derive an expression that relates a temperature θ∘X on this thermometer to the corresponding temperature t∘C on the Celsius scale.
b. (ii) Using the result of part (i), find the reading on thermometer X when the temperature is 350K.
c. (iii) When thermometer X reads 68∘X, determine the corresponding temperature on the Fahrenheit scale.