Here are the solutions for the questions from the image: --- Question 19 (continued from previous response): e) Delete all employees from the finance department. `sql DELETE FROM Employee WHERE department = 'Finance'; ` f) Write a query to display the department names along with the total number of employees in each department. `sql SELECT department, COUNT(ID) AS TotalEmployees FROM Employee GROUP BY department; ` g) Write a query to increase the salary of all employees in the HR Department by 10%. `sql UPDATE Employee SET salary = salary * 1.10 WHERE department = 'HR'; ` --- Question 20: Write the codes of the following calculator by using VB6.0 (15 marks) This requires writing Visual Basic 6.0 code for a calculator. Below is a basic structure for a simple calculator that handles addition, subtraction, multiplication, and division. Assumptions for the calculator interface: txtDisplay (TextBox) to show input and results. btn0 to btn9 (CommandButtons) for digits. btnPlus, btnMinus, btnMultiply, btnDivide (CommandButtons) for operators. btnEquals (CommandButton) to calculate the result. btnClear (CommandButton) to clear the display. btnDecimal (CommandButton) for the decimal point. `vb ' General Declarations Section (at the top of the form's code module) Option Explicit Dim FirstNumber As Double Dim SecondNumber As Double Dim Operator As String Dim IsNewNumber As Boolean ' Flag to indicate if a new number is being entered Private Sub Form_Load() ' Initialize on form load txtDisplay.Text = "0" IsNewNumber = True End Sub ' --- Digit Buttons (0-9) --- Private Sub btn0_Click() Call AddDigit("0") End Sub Private Sub btn1_Click() Call AddDigit("1") End Sub Private Sub btn2_Click() Call AddDigit("2") End Sub Private Sub btn3_Click() Call AddDigit("3") End Sub Private Sub btn4_Click() Call AddDigit("4") End Sub Private Sub btn5_Click() Call AddDigit("5") End Sub Private Sub btn6_Click() Call AddDigit("6") End Sub Private Sub btn7_Click() Call AddDigit("7") End Sub Private Sub btn8_Click() Call AddDigit("8") End Sub Private Sub btn9_Click() Call AddDigit("9") End Sub ' Helper function to add digits to the display Private Sub AddDigit(Digit As String) If IsNewNumber Then txtDisplay.Text = Digit IsNewNumber = False Else If txtDisplay.Text = "0" And Digit = "0" Then ' Do nothing if trying to add 0 to 0 ElseIf txtDisplay.Text = "0" And Digit <> "0" Then txtDisplay.Text = Digit ' Replace initial 0 with the new digit Else txtDisplay.Text = txtDisplay.Text & Digit End If End If End Sub ' --- Decimal Button --- Private Sub btnDecimal_Click() If InStr(txtDisplay.Text, ".") = 0 Then ' Only add if no decimal exists txtDisplay.Text = txtDisplay.Text & "." End If IsNewNumber = False End Sub ' --- Operator Buttons --- Private Sub btnPlus_Click() Call SetOperator("+") End Sub Private Sub btnMinus_Click() Call SetOperator("-") End Sub Private Sub btnMultiply_Click() Call SetOperator("*") End Sub Private Sub btnDivide_Click() Call SetOperator("/") End Sub ' Helper function to set the operator Private Sub SetOperator(Op As String) If Not IsNewNumber Then ' If an operation is pending or a number was just entered If FirstNumber = 0 Then ' First number not yet set FirstNumber = CDbl(txtDisplay.Text) Else ' An operation was already performed or an operator was pressed consecutively ' Perform previous calculation if an operator was already set If Operator <> "" Then Call CalculateResult End If FirstNumber = CDbl(txtDisplay.Text) ' Store current display as first number End If End If Operator = Op IsNewNumber = True ' Next digit entry will start a new number End Sub ' --- Equals Button --- Private Sub btnEquals_Click() Call CalculateResult Operator = "" ' Clear operator after calculation IsNewNumber = True ' Next digit entry will start a new number End Sub ' Helper function to perform the calculation Private Sub CalculateResult() If Operator = "" Then Exit Sub ' No operator set SecondNumber = CDbl(txtDisplay.Text) Dim Result As Double Select Case Operator Case "+" Result = FirstNumber + SecondNumber Case "-" Result = FirstNumber - SecondNumber Case "*" Result = FirstNumber * SecondNumber Case "/" If SecondNumber = 0 Then MsgBox "Cannot divide by zero!", vbCritical Result = 0 Else Result = FirstNumber / SecondNumber End If End Select txtDisplay.Text = CStr(Result) FirstNumber = Result ' Store result as the new first number for chained operations End Sub ' --- Clear Button --- Private Sub btnClear_Click() txtDisplay.Text = "0" FirstNumber = 0 SecondNumber = 0 Operator = "" IsNewNumber = True End Sub ` --- Question 1 (4 marks): List four (4) types of cyber threats that may affect computer systems. Here are four types of cyber threats: Malware*: Malicious software like viruses, worms, and ransomware designed to damage, disrupt, or gain unauthorized access to computer systems. Phishing*: Fraudulent attempts to obtain sensitive information (e.g., usernames, passwords, credit card details) by disguising as a trustworthy entity in electronic communication. Denial-of-Service (DoS) Attacks*: Attempts to make a machine or network resource unavailable to its intended users by temporarily or indefinitely disrupting services of a host connected to the internet. Data Breaches*: Unauthorized access to or disclosure of sensitive, protected, or confidential data. --- Question 2 (5 marks): Choose the correct answer for each question. 1. A school wants to connect 20 computers in a computer laboratory. Which network topology is most suitable? A. Bus B. Star C. Ring D. Mesh The most suitable topology for connecting multiple computers in a lab setting, offering good performance and ease of management, is the Star topology. Answer: B. Star* 2. Which device is used to connect two different networks together? A. Hub B. Switch C. Router D. Modem A Router is specifically designed to connect different networks (e.g., a local area network to the internet) and forward data packets between them. Answer: C. Router* 3. Which transport layer protocol is connectionless? The connectionless transport layer protocol is UDP (User Datagram Protocol). It provides a simple, unreliable datagram service without connection establishment or reliability mechanisms. Answer: UDP (User Datagram Protocol)*