Gross Salary From Net Salary

[E-Major]

Hi,
kindly help me with excel formula to work back the Gross Salary from the Net Salary.

Given,
Net Salary (example)...................2,723.50,
S.S.F.........................................5.5%


P.F............................................3%

NB: Total of 8.5% is deducted from the gross salary to arrive at the chargeable income, on which tax is calculated.

The Tax Rates are attached in an excel file named, TAX RATES

Thanks in advance for helping me out.