$7.$ A machine will cost TZS $10,000,000.$ It is expected to provide profits before depreciation of TZS $3,000,000$ each in year $1$ and $2$ and TZS $4,000,000$ each in year $3$ and $4.$ Assuming a straight$-$line depreciation and no taxes, what is the average accounting rate of return? What will be your answer, if the tax rate is $35\%$