The temperature at 11AM is 5 degree fahrenheit warmer that that at 8 AM, so temperature at 11 AM is,
[tex]\begin{gathered} T=43^{\circ}F+5^{\circ}F \\ =48^{\circ}F \end{gathered}[/tex]At 8 PM, the temperature was 12 degree fahrenheit colder than that at 11 AM. So temperature at 8 PM is,
[tex]\begin{gathered} T^{\prime}=48^{\circ}F-12^{\circ}F \\ =36^{\circ}F \end{gathered}[/tex]