The calculation of Net Domestic Product at Market Price (NDPMP) involves the following steps:
1. Determine Gross Domestic Product (GDPMP) at Market Price:
GDPMP is the sum of all economic transactions. The calculation is: \[ \text{GDP} = \text{Value of Sales to Households} + \text{Intermediate Sales between Firms} \] Total sales to households amount to ₹5,700.
Intermediate transactions (sales between firms) total ₹7,800, comprising ₹2,000 (Firm A to Firm B) + ₹1,200 (Firm A to Firm C) + ₹1,100 (Firm B to Firm A) + ₹3,500 (Firm B to Firm C).
Consequently, GDPMP equals ₹5,700 + ₹7,800 = ₹13,500.
2. Deduct Depreciation:
To arrive at Net Domestic Product (NDPMP), depreciation is subtracted from GDPMP. The formula is: NDP = GDPMP - Depreciation
NDPMP is calculated as ₹13,500 - ₹120 = ₹13,380.
Therefore, the Net Domestic Product at Market Price (NDPMP) is ₹13,380 crore.

In an economy, exclusion of _______ may lead to under estimation of the value of Gross Domestic Product (GDP).