6. The production of each product is to be determined so that profits are maximized by any electronic company that produces general and high-performance amplifiers. Each product undergoes an assembly process and an inspection process, and the available manpower per day in each process is 240 hours and 81 hours, respectively. The production of amplifiers requires 6/5 hours of assembly process and 1/2 hours of inspection process manpower per unit, and for high-performance amplifiers, 4 hours of assembly process manpower and 1 hour of inspection process manpower per unit are required. In addition, in the case of a high-performance amplifier, one special IC circuit per product is required, and it is said that only 40 lugs are procured. It makes a profit of 100,000 won per general amplifier and 500,000 won per high-performance amplifier. Answer the next question. 1) Express this problem in a linear planning model and find an optimal solution. (using a simplex tableau) 2) Find an increase in profit as the assembly manpower increases by one unit. 3) Find the range of benefits and available personnel for each amplifier whose optimal solution does not change. 4) In addition to the existing amplifiers, the company is considering the production of tuners. In the case of a tuner, an assembly process of 5 hours per unit, an inspection process of time, and one special IC circuit are required, and the net profit is 750,000 won per unit. Is it desirable to produce a tuner? Write the answer and explain why.