ANSWER
V = 320π cm³ ≈ 1005.31 cm³
EXPLANATION
The volume of the tube is the difference between the volume of the outer cylinder and the volume of the inner cylinder.
The volume of a cylinder of length h and radius r is,
[tex]V=\pi\cdot r^2\cdot h[/tex]
The length of both cylinders of this tube is the same, h₁ = h₂ = 20cm. The radius of the outer cylinder r₂ = 5cm and the radius of the inner cylinder is r₁ = 3cm. The volume of the tube is,
[tex]V_{tube}=V_2-V_1=(\pi\cdot r^2_2\cdot h)-(\pi\cdot r^2_1\cdot h)=\pi\cdot h\cdot(r^2_2-r^2_1)[/tex]
Replace with the values and solve,
[tex]V_{tube}=\pi\cdot20cm\cdot((5cm)^2-(3cm)^2)=\pi\cdot20\operatorname{cm}\cdot(25-9)cm^2=\pi\cdot20\operatorname{cm}\cdot16cm^2[/tex]
Hence, the volume of the tube is,
[tex]V_{tube}=320\pi cm^3\approx1005.31cm^3[/tex]
