Given data:
The initial temperature is T=80° F.
The final temperature is T'=70°F.
The expression for the percentage of temperature drop is,
[tex]\Delta=\frac{T-T^{\prime}}{T}\times100[/tex]Substitute the given values in the above expression.
[tex]\begin{gathered} \Delta=\frac{80^{\circ}F-70^{\circ}F}{80^{\circ}F}\times100 \\ =(0.125)\times100 \\ =12.5 \end{gathered}[/tex]Thus, the percentage drop is 12.5%, so third option is correct.
