Answer: 65°
Step-by-step explanation:
[tex]E=w(t_f-t_o)\\\\E: 10\ cubic\ feet\times \dfrac{1000\ BTU}{1\ cubic\ foot}\times \ 60\%\quad \rightarrow \quad E=6000\ BTU\\\\\\w:50\ gallons\times \dfrac{8\ pounds}{1\ gallon}\quad \rightarrow \quad w=400\ pounds\\\\\\\\E=w(t_f-t_o)\\\\6000=400(t_f-50)\\\\\dfrac{6000}{400}=\dfrac{400(t_f-50)}{400}\\\\.\quad 15=t_f-50\\\\\\.\quad 15=t_f-50\\.\ \underline{+50}\quad \underline{\quad \ +50}\\.\quad 65=t_f[/tex]
