QUESTION1:

26.   1 1 1 1 1 1
      2 2 2 2 2
      3 3 3 3
      4 4 4
      5 5
      6

SOLUTION:

public class Patterns {
    public static void main(String[] args) {
        Pattern(6);
    }
    static void Pattern(int n){
        for(int i = 1; i <= n; i++){

            for(int j = 0; j <= n-i; j++){
                System.out.print(i + " ");
            }
            System.out.println();
        }
    }

}

QUESTION2:

27.   1 2 3 4  17 18 19 20
        5 6 7  14 15 16
          8 9  12 13
            10 11

SOLUTION:

public class Patterns {
    public static void main(String[] args) {
        Pattern(4);
    }
    static void Pattern(int n){
        int c1 = 1;
        int c2 = 4*n + 1;

        for(int i = 1; i <= n; i++){

            for(int j = 1; j < i; j++){
                System.out.print(" ");
            }

            int c3 = c2;

            for(int j = 1; j <= (n-i+1)*2; j++){
                if(j <= n-i+1){
                    System.out.print(c1 + " ");
                    c1++;
                }else{
                    System.out.print(c3 + " ");
                    c3++;
                }
            }
            System.out.println();
        
            c2 -= (n-i);
        }
    }

}

QUESTION3:

28.      *
        * *
       * * *
      * * * *
     * * * * *
      * * * *
       * * *
        * *
         *

SOLUTION:

public class Patterns {
    public static void main(String[] args) {
        Pattern(5);
    }
    static void Pattern(int n){
//run the outer loop as many times as the number of rows
     for(int i = 1; i < 2*n; i++){

        int c = i <= n ? i : 2*n - i;

        for(int j = 1; j <= n-c; j++){
            System.out.print(" ");
        }

        for(int k = 1; k <= c; k++){
            System.out.print("* ");
        }
        System.out.println();
     }
        }
    }

QUESTION4:

30.         1
          2 1 2
        3 2 1 2 3
      4 3 2 1 2 3 4
    5 4 3 2 1 2 3 4 5

SOLUTION:

public class Patterns {
    public static void main(String[] args) {
        Pattern(5);
    }
    static void Pattern(int n){
//run the outer loop as many times as the number of rows
     for(int i = 1; i <= n; i++){

//print spaces
        for(int j = 1; j <= n-i; j++){
            System.out.print(" ");
        }

//print rhs of pattern
        for(int k = i; k >= 1; k--){
            System.out.print(k);
        }

//print lhs of pattern
        for(int l = 2; l <= i; l++){
            System.out.print(l);
        }
        System.out.println();
     }
        }
    }

Thank you for reading. If you have any queries then, please let me know in the comment section. I will surely be responsive toward it.