How do we count the various goods and services and know the total production in each sector and why?

(a) The value of final goods and services in the three sectors are calculated and then added up to know the total production in each sector.
(b) only final goods and services are counted because the value of final goods already includes the value of all the intermediate goods that are used in making the final goods. For example, the value of a table (suppose ₹ 2,000) includes the value of wood (₹ 1,000) and polish (₹ 500). So the value of wood and polish is not counted separately.