Solution in JavaScript :

// Declare second integer, double, and String variables. let secondInt; let secondDouble; let secondString

// Read and save an integer, double, and String to your variables.
secondInt = parseInt(readLine());
secondDouble = parseFloat(readLine());
secondString = readLine();

// Print the sum of both integer variables on a new line.
console.log(i + secondInt);

// Print the sum of the double variables on a new line.
console.log((d + secondDouble).toFixed(1));

// Concatenate and print the String variables on a new line
// The 's' variable above should be printed first.
console.log(s + secondString);