Compute the OPT A. JJ, non-vat registered taxpayer, operates a convenience store from which the gross receipts from sales, and payments on purchases from VAT registered suppliers were as follows (net of taxes): Sales of processed food items 280,000 Sales of non food items 220,000 Purchases of processed food items 100,000 Purchases of non food items 80,000 Salaried of helpers 48,000 Philippine tax