economic problem ( URGEN HELP AND THANKS)

The main reason is that as the total cost on buffet is fixed, the average cost per dish would fall as you consume more and more food. One the other hand, your total cost would be increased if you order more and more dishes in a standard restaurant. Furthermore, the marginal cost per dish would be lowered if you consume expensive food in buffet, but the marginal cost to consume the same food would be higehr in normal standard restaurant. Therefore, someone would become a glutton at a buffet style restaurant but he will become a light eater at restaurant.

You can answer this question by looking at the demand curve. For explanation's sake, assume each item in the menu is the same price.

Remember that the demand curve is the marginal utility. In a regular meal, you order the food until the marginal utility equals the price of food. In other words, you order the food according to your demand for food. Given any price, you will not order where the price of food is higher than the demand, or the marginal utility.

In a buffet meal, you pay a lump sum and each additional item costs you nothing. In this case, if the marginal utility from eating another oyster is positive, why not have it. In theory, a consumer will eat until his marginal utility from the food is 0 because price is no longer a concern.

For the same person, he will consume until marginal utility equals price in a regular restaurant but will consume until marginal utility is zero in a buffet dinner. That explains why a person will eat more in a buffet restaurant.