Answer:
Purposes of Data Layer, in the Layered model for web applications are as following:-
1. The data Layer,is the third layer and it takes care of the all the operations concerning the database level.
2. This data layer gets a command from the application layer to send a query to the database and will process this command according to the type of database that is used.
3. It will ensure that the correct connections to the database are set.
4. It is represented by the Database.
 
        
             
        
        
        
Answer:
Handle the exception in a catch block or throw the exception to the method that called this method.
Explanation:
The try and catch statements occur in pairs. The try statement allows the user to define a block of code to be tested for errors while it is being executed.
The catch statement allows the user to define a block of code to be executed, if an error occurs in the try block.
If an exception is checked by a method, the method either handles the exception in a catch block or throw the exception to the method calling it.
 
        
                    
             
        
        
        
<span>When it comes to linear programming, the solution which would be effective in satisfying all constraints in the given program in a simultaneous matter is called that of feasible programming. This is due to the fact that the program can satisfy all requirements at the same time.</span>