Alex, Boris and Chris enter into a financial arrangement. Under this arrangement, Alex will pay Boris $10,000 today. Boris will pay Alex $K at the end of 3 years. Boris will also pay Chris $6, 000 at the end of 4 years. Chris will pay Alex $K at the end of 8 years. It is known that Alexs annual effective interest rate on his financial arrangement is 6.5%. (a) Determine K. (b) Find Chriss annual effective interest rate on his financial arrangement.