Vat & service tax bifurcation from all inclusive amount for billing

How to break up 14.5% VAT & 15% Service Tax from an all inclussive amount

for Example Amount Inclussive of VAT & Service tax is 12,20,000/-

I want to calculate 14.50% VAT on 70% of Amount Before tax

and 15% ST on 30% of Amount before tax

For this, I have to find out Tax Before Tax

Anybody can help me.