A 234−kg coil of sheet steel is 1.5 mm thick and 40 cm wide. How long is the steel in the coil?

since the density of steel is about 7.85 g/cm^3, this means you have

234kg * 1000g/kg 1cm^3/7.85g = 198928 cm^3 of steel
so now you want the length L of the sheet, where
0.15*40L = 198928
L = 33154.7 cm or 331.547m