Calculate the density of nickel in kg/m³

A thin rectangular plate 350mm by 250mm is totally covered on both sides with nickel 0.12mm thick in 8.25h. The current required would ,if supplied to voltmeter ,cause 0.0805kg of silver to be deposited in 1h. If the E.C.E of nickel is 304×10^-9kg/C ,Calculate the density of nickel in kg/m³ ,if the E.C.E of silver is taken as 1118×10^-9kg/C.