Final answer:
The firm should invest $52 million in R&D due to spillover benefits. The opportunity cost of financial capital is 6% for HighFlyer Airlines.
Step-by-step explanation:
The firm should invest $52 million in R&D. The opportunity cost of financial capital is 6% for HighFlyer Airlines. The equilibrium point where the demand for financial capital meets the cost of borrowing is $30 million, but society finds it optimal to have $52 million of investment due to spillover benefits. If the firm could keep the social benefits of its investment, its demand curve for financial capital would show willingness to borrow $52 million.