Hi, in its simplest form just multiply 75 by 0.5833333
A. VAT is calculated on selling price /120 x 100 (0.83333)
B. Profit 70% of selling price x 0.7
C. Selling price = 0.7 x 0.8333 (0.58333)
Simple spreadsheet would have cell a1 Sell Price, a2 VAT (0.8333), a3 Profit (0.7), a4 Cost Price =a1*a2*a3