title: How to write a function multiple(5)(6) that will return 30?
body: <p>I am trying to understand how can we achieve such a function in JS, and what is the main use of this approach? </p>
  
  <p>multiple(5) will return 5 
  multiple(5)(6) will return 30</p>
  
  <p>how can we achieve such a function in JavaScript?</p>