Please solve and explain.

Assume that the following equations characterize a large open economy: (1) Y = 5,000 (2) Y = C+/+G+NX (3) C = 1/2(Y - T) (4) 1 = 2,000 - 100r (5) NX = 500 - 5001 (6) CF = -100r (7) CF = NX (8) G = 1,500 (9) T = 1,000. In this economy, what is the value of the real interest rate, r? 1.5 2.5 3.5 None of the above