Consider the following labor planning problem. there are four overlapping shifts and each worker works for two consecutive shifts once they start working. minimum number of workers needed during the four shifts are 12, 15, 16 and 14 respectively. management must decide how many employees to schedule to start work on each shift with the objective to minimize the total number of employees required for all 4 shifts.

The answer would be Barter System.

Explanation:

In today's world, companies sell their product of services to the people and take money in exchange of their product or service. People pay money to buy something they want. But long ago, before the invention of money or currency, there was a system in which goods were exchanged for goods and services were exchanged for services. This system was called as the Barter System. In this system, people exchange their products or services to other people for their product or services. No money was involved. If people wanted to buy some products, then they should exchange their own product so that they can buy that specific product that they need.