Given,
Internal diameter of cylindrical tube = 10.4 cm
internal radius of tube = \(\frac{10.4}{2}\) = 5.2 cm
length of tube = 25 cm
thickness of metal = 8 mm = 0.8 cm
so,
Outer radius of tube = R = 5.2 + 0.8 = 6 cm
Volume of metal = π(R2 - r2) x l = \(\frac{22}{7}\)(62 - 5.22) x 25 = 704 cm3