Final answer:
The nation's GDP, including trees, lumber, and bookshelves, is $600.
Step-by-step explanation:
The nation's GDP can be calculated by adding up the value of the final goods produced, including trees, lumber, and bookshelves. In this case, the value of the final goods is:
- The value of the trees = $200
- The value of the lumber = $150
- The value of the bookshelves = $250
Adding up these values gives us $200 + $150 + $250 = $600. Therefore, the nation's GDP is $600.