$1.$ A book value of the corp. is $70$ mil USD which generate a $40\%$ return after tax. Assume tax is charged at the rate of $30\%.$ The corporation has several fixed costs include $10\%$ interest charged on a $6$ mil bank loan and $1$ mil of equipment and fittings depreciation and the cost of goods sold is $4$ mil per year. The manager estimates that operating expenses will be $8$ mil. Calculate the corporation sales?