This C tutorial explains how to use the #define preprocessor directive in the C language. In the C Programming Language, the #define directive allows the definition of macros within your source code. These macro definitions allow constant values to be declared for use throughout your code. Macro definitions are not variables and cannot be changed by your program code like variables.
Price Ceilings. If the price ceiling is above the market price, then there is no direct effect. If the price ceiling is set below the market price, then a shortage is created; the quantity demanded will exceed the quantity supplied. The shortage may be resolved in many ways.
Suppose market demand and supply are given by Qd = 100 - 2P and QS = 5 + 3P. If a price ceiling of $15 is imposed, there will be a surplus of 40 units. there will be neither a surplus or shortage. there will be a shortage of 40 units. there will be a shortage of 20 units.