Crib Makers makes two cribs called Model 1 and Model 2.Each Model 1 crib is sold for $300, and each Model 2 crib is sold for $400. Both models use two types of wood, i.e., oak, and black walnut. The time and material needed to build each model are shown in the table below.

	Oak (board feet)	Black Walnut (board feet)	Time (hours)
Model 1	20	5	10
Model 2	25	7	15

Crib Makershas 500 board feet of oak, 100 board feet of black walnut and 240 hours for the next month. Crib Makers wants to maximum the total value of cribs production given the constraints above, and has formulated the problem as follows:

x₁ - The number of Model 1 cribs

x₂ - The number of Model 2 cribs

max: 300x₁ + 400x₂

s.t. 20x₁ + 25x₂ 500 C1: Oak Constraint

5x₁ + 7x₂ 100 C2: Black Walnut Constraint

10x₁ + 15x₂ 240 C3: Time Constraint

x₁, x₂ 0

a) Solve the LP by using Excel Solver. How many Model 1 and Model 2 cribs should Baby Care Inc. make, respectively?What is the optimal objective value?

b) List all the binding constraint(s) by using C1, C2 and C3. What is the shadow price for each of the binding constraint(s)?

c) According to the shadow price, if the time constraint increases from 240 hours to 241 hours, how will that affect the objective value?