Survey evidence from forex traders indicates support for the economic fundamental's impact on exchange rates:

Suppose a chemical plant regularly dumps chemicals into a river that must be cleaned up before farmers located downstream can use the water on their crops

Dumping the chemicals into the river saves the chemical plant $750,000 in yearly disposal costs and cleaning the water costs farmers $825,000 each year. Explain what the benevolent social planner would like to see happen in this case.

If real GDP in a closed economy is $40 billion, consumption is $20 billion, and government purchases are $10 billion, what is investment?

A) $10 billion B) $30 billion C) $40 billion D) $70 billion