The temperature of a room (T) is a function of how far the window is open (W) according to T(W) = 40 - 0.2W. How long you sleep (S, measured in hours) is a function of the temperature according to S(T) = 14 - T/5. Find how long you sleep as a function of how far the window is open. How long would you sleep if the window was 10 cm2 open?
The above series of functional compositions describe connections between several measurements.