Answer
514.23 grams Pb.
Work Step by Step
Volume of iron = $\frac{Mass \,of\, iron}{Density\, of\, iron}=\frac{355 g}{7.87 g/cm^{3}}=45.108\,cm^{3}$
Volume of lead (Pb) is also same i.e $45.108\,cm^{3}$.
So, mass of lead (Pb) $=Volume\times\,Density=45.108\,cm^{3}\times11.4\,g/cm^{3}=514.23 g.$
