The following formula is used to calculate the specific gravity of a material. SG = Ï / ÏW. Where SG = specific gravity, Ï = density of the material (kg/m3), ÏW = density of water ( kg/m3). The reference density of water at 4oC (39oF) is used as the reference as these are the conditions of maximum density.
Donât throw bank statements away after six years. August 12, 2013 85237 ViewsFacebook: 808Twitter: 41. The conventional wisdom is you only need to keep bank, credit card and other personal finance documents for six years. This is because HMRC (the taxman) can only ask you to go back that far if youâre being investigated for tax purposes.
1 How long to keep records: Keep the records for at least three months. 2  Review that all the purchases are correctly entered in your bank and credit card statements. 3  Review your monthly bills.4  If there is a discrepancy, then keep the document until you resolve the problem. How long to keep records: Keep the records for at least three months. 2  Review that all the purchases are correctly entered in your bank and credit card statements. 3  Review your monthly bills.