when pressure is constant we can use the charles law:
[tex]\frac{V_1}{T_1}=\frac{V_2}{T_2}[/tex]in this case we need to solve for T2 and use the data provided in the text:
[tex]T_2=\frac{V_2T_1}{V_1}=\frac{14L\cdot299K}{17L}=246K[/tex]So the final Temperature is 246K