Problem 1. (10 Points) Some programming languages are typeless. What are the obvious advantages and disadvantages of having no types in a language? Problem 2 (10 Points) Assume the following JavaScript program was interpreted using static-scoping rules. What value of x is displayed in function sub1? Under dynamic-scoping rules, what value of x is displayed in function sub1? var x; function sub1() { document.write("x = " + x + ""); } function sub2() { var x; x = 10; sub1(); } x = 5; sub2(); Problem 3 (30 Points) Consider the following JavaScript program: var x, y, z; function sub1() { var a, y, z; function sub2() { var a, b, z; . . . } . . . } function sub3() { var a, x, w; . . . } List all the variables, along with the program units where they are declared, that are visible in the bodies of sub1, sub2, and sub3, assuming static scoping is used.