An electronics company has a contract to deliver 20000 radios within the
next four weeks. The client is willing to pay $20 for each radio delivered by the end of the
first week, $18 for those delivered by the end of the second week, $16 by the end of the
third week, and $14 by the end of the fourth week. Since each worker can assemble only
50 radios per week, the company cannot meet the order with its present labor force of 40;
hence it must hire and train temporary help. Any of the experienced workers can be taken
off the assembly line to instruct a class of three trainees; after one week of instruction,
each of the trainees can either proceed to the assembly line or instruct additional classes.
At present, the company has no other contracts; hence some workers can become idle
once the delivery is completed. All of them, whether permanent or temporary, must be
kept on the payroll till the end of the fourth week. The weekly wages of a worker, whether
assembling, instructing or being idle, are $200; the weekly wages of a trainee are $100.
The production costs, excluding the worker’s wages, are $5 per radio.
The company’s aim is to maximize the total net profit. Formulate as an LP problem
(not necessarily in the standard form).

does any1 know how to put thi sin an LP model, or as an AMPL code?