A company separates nickel, lead, and kryptonite from ore by the floatation separation process, which has three steps: oiling, mixing, and separation. These steps must be applied for 2, 4, and 1 hour respectively to produce one unit of nickel; 2, 2, and 1 hour respectively to produce one unit of lead; and 1, 1, 4 hours respectively to produce one unit of kryptonite. Because of limited access to equipment, the oiling and separation phases can each be in operation for a maximum of 14 hours per week, and the mixing process can be in operation for a maximum of 18 hours per week. The company makes a profit of $40 per unit of nickel, $55 per unit of lead, and $50 per unit of kryptonite. Assuming that the demaind for each metal is unlimited, how many units of each metal should the company produce each week to maximize its profit?

Number of units of nickel =

Number of units of lead =

Number of units of kryptonite =