[tex]\begin{gathered} In\text{ 15 minute discharge water is=5-2}=3\text{ gallon} \\ \text{1 gallon will discharge in }\Rightarrow\frac{15}{3}=5\text{ minute/ gallon} \\ so,\text{ 5 gallon of water will be empty in} \\ \Rightarrow5\text{ minute/gallon }\times5\text{ gallon}=25\text{ minute} \end{gathered}[/tex]
