An investor has $1,200,000 to invest and wants to maximize the money they will receive at the end of one year. They can invest in condos, apartments and houses. The profit after one year, the cost and the number of units available are shown below.

Variable	Investment	Profit ($1,000)	Cost ($1,000)	Number Available
X1	Condos	6	50	30
X2	Apartments	12	90	16
X3	Houses	9	100	12

The mathematical formulation of this ILP problem is given below:

MAX:6 X1 + 12 X2 + 9 X3

Subject to:

50X1 + 90 X2 + 100 X3 1200

X1 30

X2 16

X3 12

Xi 0 and integer

Use Solver to find the optimal solution of this ILP problem

(X1, X2, X3)=(1, 5, 0)

(X1, X2, X3)=(3, 6, 0)

(X1, X2, X3)=(8, 0, 0)

(X1, X2, X3)=(2, 12, 0)