Answer:
import java.util.Scanner; 
 
public class Program 
{ 
 public static void main(String [] Args) 
 { 
 int totalAGrades = 0, totalBGrades = 0, totalCGrades = 0, totalDGrades = 0, totalFGrades = 0, counter=0,maximum = 0, minimum = 9999, num, total = 0,smallest = 0,largest = 0; 
 Scanner in = new Scanner(System.in); 
 System.out.println("Enter exam percentage: "); 
 System.out.println("Enter a negative examScore: "); 
 int examScore = in.nextInt(); 
 while(examScore > 0) 
 { 
 counter++; 
 if(examScore < 0){ 
 break;} 
 
 
 else if(examScore > maximum){ 
 maximum = examScore;} 
 else if(examScore < minimum) { 
 minimum = examScore;} 
 
 total = total + examScore; 
 
 if(examScore <= 50 && examScore>0) 
 smallest = examScore; 
 if(examScore > 90 && examScore <=100) 
 largest = examScore; 
 
 if(examScore>=90 && examScore<=100) 
 totalAGrades++; 
 else if(examScore>=80 && examScore<=89) 
 totalBGrades++; 
 else if(examScore>=70 && examScore<=79) 
 totalCGrades++; 
 else if(examScore>=60 && examScore<=69) 
 totalDGrades++; 
 else if(examScore>=0 && examScore<=59) 
 totalFGrades++; 
 examScore = in.nextInt(); 
 
 } 
 System.out.println("Total number of scores is = " + counter ); 
 System.out.println("Total Number of each Letter grade : " + counter); 
 System.out.println("Percentage of total for each letter grade : "); 
 System.out.println("Total number of A grades = "+ totalAGrades); 
 System.out.println("Total number of B grades = "+ totalBGrades); 
 System.out.println("Total number of C grades = "+ totalCGrades); 
 System.out.println("Total number of D grades = "+ totalDGrades); 
 System.out.println("Total number of F grades = "+ totalFGrades); 
 
 System.out.println("Lowest exam Score is :"+smallest); 
 System.out.println("Highest exam Score is :"+largest); 
 System.out.println("Average exam Score = "+ (total / counter)); 
 
 } 
} 
Step-by-step explanation:
- Get the exam information from user as input and run a while loop until examScore is greater than zero.
- Use conditional statement to check the scores of students and increment the relevant grade accordingly.
- Finally display all the information including grades and scores.