The 18 % off of the listed price x can be denoted as,
[tex]\frac{100-18}{100}x=0.82x[/tex]
18% more than the amount x can be denoted as,
[tex]\frac{100+18}{100}x=1.18x[/tex]
3/10 of the origianl voulme x drained out is denoted as,
[tex]x-\frac{3}{10}x=\frac{10x-3x}{10}=\frac{7x}{10}[/tex]
3/10 stock is added,
[tex]x+\frac{3}{10}x=\frac{10x+3x}{10}=\frac{13x}{10}[/tex]
