If you need to write a do-while loop that will ask the user to enter a number between 2 and 5 inclusive, and will keep asking until the user enters a correct number, what is the loop condition?

No, a do loop only loops once. You should use a While loop or For loop, Example below in C++:

 for (tries = 0; ; tries++){
      if (answer == guess)
      {
         cout << "You guessed it!";
         cout << "And it only took you " << tries << " tries.\n";
         break;
      }
      if (answer < guess)
      {
         cout << "Higher\n"<<endl;
         cin >> answer;
      }

      if ( answer > guess)
      {
         cout << "Lower\n"<<endl;
         cin >> answer;
      }
   }}

/*

Write an expression that executes the loop while the user enters a number greater than or equal to 0.

Note: These activities may test code with different test values. This activity will perform three tests,

with user input of 9, 5, 2, -1, then with user input of 0, -17, then with user input of 0 1 0 -1.  

*/

import java.util.Scanner;

public class NonNegativeLooper {

  public static void main (String [] args) {

     Scanner scnr = new Scanner(System.in);

     int userNum;

     userNum = scnr.nextInt();

     while ( userNum >= 0 ) {

        System.out.println("Body");

        userNum = scnr.nextInt();

     }

     System.out.println("Done.");

  }

}

Explanation:

while ( userNum >= 0 ) { // this line executes the loop while the user enters a number greater than or equal to 0.