import java.util.Scanner;

public class Solution { public static void main(String[] args) { int i = 4; double d = 4.0; String s = "HackerRank ";

    Scanner scan = new Scanner(System.in);

    // Declare variables
    int i2;
    double d2;
    String s2;

    // Read inputs
    i2 = scan.nextInt();
    d2 = scan.nextDouble();
    scan.nextLine();      // consume leftover newline
    s2 = scan.nextLine();

    // Print results
    System.out.println(i + i2);
    System.out.printf("%.1f\n", d + d2);
    System.out.println(s + s2);

    scan.close();
}

}

agreed on confunsing wording

python3

if __name__ == '__main__':
    i = int(4)
    d = float(4.0)
    s = str('HackerRank')
    
    a = int(input().strip())
    b = float(input().strip())
    c = str(input().strip())
    
    print(i+a)
    print(b+d)
    print(s, c)

I don't know if it's just me but the wording was super confusing.

in C# this works

  // Declare second integer, double, and String variables.
    int secondInteger;
    double secondDouble; 
    string secondText;

    // Read and save an integer, double, and String to your variables.
     secondInteger = int.Parse(Console.ReadLine());
     secondDouble = double.Parse(Console.ReadLine());
     secondText = Console.ReadLine();

    // Print the sum of both integer variables on a new line.
    Console.WriteLine(secondInteger+i);

    // Print the sum of the double variables on a new line.
    double var3 = secondDouble+d;
     Console.WriteLine(var3.ToString("F1"));

    // Concatenate and print the String variables on a new line
    // The 's' variable above should be printed first.
    Console.WriteLine(s+""+secondText);


}

here is Day 1 data types solution in python, java, c++, c and javascript - https://programmingoneonone.com/hackerrank-day-1-data-types-30-days-of-code-solution.html