4. The payoff matrix below shows the payoffs (in millions of dollars) for two firms, A and B, for two different strategies, investing in new capital or not investing in new capital. Firm B | | Invest | Not Invest | | --- | --- | --- | | Invest | 20 for A | 70 for A | | | 20 for B | 5 for B | | Firm A | 5 for A | 50 for A | | Not invest | 70 for B | 50 for B | An industry spy from firm A comes to firm B and offers to pay B in exchange for B's certain and enforceable promise to not invest. What is the most that firm A will be willing to pay B to not invest? (10%)