again, please help. i dont know any of this

[tex]\textrm {Cylinder volume :}[/tex]
[tex]\mathrm {Volume = \pi r^{2}{h}}[/tex]
[tex]\mathrm {Volume = 3.14 \times (\frac{4}{2})^{2} \times 3}[/tex]
[tex]\mathrm {Volume = 3.14 \times 12}[/tex]
[tex]\mathrm {Volume = 37.68cm^{3}}[/tex]
[tex]\textrm {Rectangular prism volume :}[/tex]
[tex]\mathrm {Volume = length \times width \times height}[/tex]
[tex]\mathrm {Volume = 6 \times 5 \times 7}[/tex]
[tex]\mathrm {Volume = 30 \times 7}[/tex]
[tex]\mathrm {Volume = 210cm^{3}}[/tex]
[tex]\textrm {Total volume of composite figure :}[/tex]
[tex]\textrm {Volume of cylinder + volume of rectangular prism}[/tex]
[tex]\mathrm {37.68 + 210}[/tex]
[tex]\mathrm {247.68cm^{3}}[/tex]