Income statements and balance sheets follow for E.I. DuPont de Nemours and Company. Refer to these financial statements to answer the requirements.

E. I. du Pont de Nemours and Company Consolidated Income Statements For The Year Ended December 31,
($ millions)	2016	2015
Net sales	$ 24,594	$ 25,130
Cost of goods sold and other operating charges	15,155	15,571
Selling, general and administrative expenses	4,319	4,615
Research and development expense	1,641	1,898
Other (income) expense, net (non-operating)	(708)	(697)
Interest expense	370	342
Employee separation/asset related charges(income), net	552	810
Income from continuing operations before income taxes	3,265	2,591
Provision for income taxes on continuing operations	744	696
Income from continuing operations after income taxes	2,521	1,895
Income from discontinued operations after income taxes	4	64
Net income	2,525	1,959
Less: Net income attributable to noncontrolling interests	12	6
Net income attributable to DuPont	$ 2,513	$ 1,953

E. I. du Pont de Nemours and Company Consolidated Balance Sheets As of December 31,
($ millions)	2016	2015
Assets
Cash and cash equivalents	$ 4,605	$ 5,300
Marketable securities	1,362	906
Accounts and notes receivable, net	4,971	4,643
Inventories	5,673	6,140
Prepaid expenses	506	398
Total current assets	17,117	17,387
Net property, plant and equipment	9,231	9,784
Goodwill	4,180	4,248
Other intangible assets	3,664	4,144
Investment in affiliates	649	688
Deferred income taxes	3,308	3,799
Other assets	1,815	1,116
Total assets	$39,964	$41,166

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Table continued

E. I. du Pont de Nemours and Company Consolidated Balance Sheetscontinued As of December 31,
(in millions)	2016	2015
Liabilities and equity
Accounts payable	$ 3,705	$ 3,398
Short-term borrowings and capital lease obligations	429	1,165
Taxes payable	101	173
Other accrued liabilities	4,662	5,580
Total current liabilities	8,897	10,316
Long-term borrowings and capital lease obligations	8,107	7,642
Other liabilities	12,333	12,591
Deferred income taxes	431	417
Total liabilities	29,768	30,966
Common stock, $0.30 par value	285	288
Preferred stock, without par value cumulative	237	237
Additional paid-in capital	11,190	11,081
Reinvested earnings	14,924	14,510
Accumulated other comprehensive loss	(9,911)	(9,396)
Common stock held in treasury	(6,727)	(6,727)
Total DuPont stockholders equity	9,998	9,993
Noncontrolling interests	198	207
Total equity	10,196	10,200
Total liabilities and stockholders equity	$39,964	$41,166

Required

a. Compute net operating profit after tax (NOPAT) for 2016 and 2015. Assume that combined federal and state statutory tax rate is 37% for both years.

b. Compute net operating assets (NOA) for 2016 and 2015.

c. Compute return on net operating assets (RNOA) for 2016 and 2015. Net operating assets are $13,239 million in 2014.