To represent the given scenario using pseudocode, you can follow these steps:
1. Declare variables to store the total percentage marks of all students, the count of students, and the class average.
2. Initialize the total percentage marks and count of students to zero.
3. Start a loop to input the details of each student until the student name "ZZZ" is entered.
4. Within the loop, input the name, address, and exam percentage of the student.
5. Calculate the total percentage marks by adding the exam percentage to the current total.
6. Increment the count of students by 1.
7. End the loop when the student name "ZZZ" is entered.
8. Calculate the class average by dividing the total percentage marks by the count of students.
9. Start another loop to output the details of each student.
10. Within the loop, print the name, address, and percentage of each student.
11. End the loop.
12. Finally, print the total percentage marks and the class average.
Here is the pseudocode representation of the scenario:
```
totalPercentage <- 0
countStudents <- 0
WHILE True:
PRINT "Enter the student name (Enter 'ZZZ' to finish): "
INPUT studentName
IF studentName equals "ZZZ":
BREAK
PRINT "Enter the student address: "
INPUT studentAddress
PRINT "Enter the exam percentage of the student: "
INPUT examPercentage
totalPercentage <- totalPercentage + examPercentage
countStudents <- countStudents + 1
PRINT "----------------------"
PRINT "Name: " + studentName
PRINT "Address: " + studentAddress
PRINT "Percentage: " + examPercentage
PRINT "----------------------"
classAverage <- totalPercentage / countStudents
PRINT "Total Percentage Marks: " + totalPercentage
PRINT "Class Average: " + classAverage
```
Please note that this is just pseudocode, it does not represent the actual programming language syntax, and thus it cannot be directly executed.