public void repopulation() {
    int[][] ngrid = new int[grid.length][grid[0].length];
    for(int i = 0; i < grid.length; i++) {
        for(int j = 0; j < grid[0].length; j++) {
            int random = (int) (Math.random() * MAX) + 1;
            while (random % 10 != 0 || random % 100 == 0) {
                random = (int) (Math.random() * MAX) + 1;
            }
            ngrid[i][j] = random;
        }
    }
    grid = ngrid;
}

b)

public int countIncreasingCols() {
   int c = 0;

   for (int i = 0; i < grid[0].length; i++) {
      boolean alr = true;

      for (int j = 1; j < grid.length; j++) {
         if (grid[j][i] < grid[j - 1][i]) {
            alr = false;
         }
      }

      if (alr) {
         alr = false;
      }
   }

   return c;
}