USING C# Write a console app that inserts 30 random letters into a List. Perform the following queries on the List and display your results: [Hint: Strings can be indexed like arrays to access a character at a specific index.] Use LINQ to sort the List in ascending order. Use LINQ to sort the List in descending order. Display the List in ascending order with ONLY DUPLICATES

Write a program that reads in a line consisting of a students name, Social Security number, user ID, and password. The program outputs the string in which all the digits of the Social Security number and all the characters in the password are replaced by x. (The Social Security number is in the form 000-00-0000, and the user ID and the password do not contain any spaces.) Your program should not use the operator [] to access a string element. Use the appropriate functions described in Table 7-1.

Write an Add method that adds the contents of the decPrice variable to the lstPrices control.

(List maintenance) a. Write a complete C++ program that can be used to update an ordered list of numbers. Use the list of numbers shown in Figure 7.13 to test that your program is working correctly. b. Test the program you wrote for Exercise 4a, using a new part number of 86 with the list of numbers shown in Figure 7.13. This test should place this new code at the beginning of the existing list. c. Test the program you wrote for Exercise 4a, using a part number of 200 with the list of numbers shown in Figure 7.13. This test should place this new part number at the end of the existing list