P-16 Gothong Inc., sells automatic voltage regulators costing P700 at the price of P1,200. Cardinal Audio buys a dozen voltage regulators on installment and trade-in six (6) of its units at a trade in value of P300 eah. Gothong Inc., spends P25 to recondition the old units and sells them at P315. Gothong Inc., expects 10 percent gross profit from the sale of voltage regulators. How much is the over-allowance granted by Gothong Inc., on the trade-in? a. P249 b. P150 c. P339 d. P189