A country has the following data: GDP at market prices = ₦120,000 billion; Indirect taxes = ₦15,000 billion; Subsidies = ₦5,000 billion; Depreciation = ₦8,000 billion; Net factor income from abroad = −₦3,000 billion. What is the National Income (NNP at factor cost)?

Step 1: GNP at market prices = GDP + Net factor income from abroad = ₦120,000 − ₦3,000 = ₦117,000 billion. Step 2: NNP at market prices = GNP − Depreciation = ₦117,000 − ₦8,000 = ₦109,000 billion. Step 3: National Income (NNP at factor cost) = NNP at market prices − Net indirect taxes = ₦109,000 − (₦15,000 − ₦5,000) = ₦109,000 − ₦10,000 = ₦99,000 billion.