Could we use only one "answer" variable for this challenge?

I have it pretty much the same as the professor has it but I use it only one "answer" variable and used it for all the 5 prompts. I don't know is that is or it isn't a good practice. Here is my code:

// quiz begins, no answer counter as correct var counter = 0;

//ask questions var answer = prompt("What is the best programming language?");

if (answer.toLowerCase() === 'javascript') { counter += 1; }

answer = prompt("You should be putting a semicolon after a if condition?");

if (answer.toLowerCase() === 'no' || answer.toLowerCase() === 'n') { counter += 1; }

answer = prompt("What function do we use in javascript to lover case all letters?");

if (answer.toLowerCase() === 'tolowercase()' || answer.toLowerCase() === 'tolowercase') { counter += 1; }

answer = prompt("What function do we use in javascript to upper case all letters?");

if (answer.toLowerCase() === 'touppercase()' || answer.toLowerCase() === 'touppercase') { counter += 1; }

answer = prompt("What math function do we use in javascript to generate random numbers?");

if (answer.toLowerCase() === 'math.random()' || answer.toLowerCase() === 'random()' || answer.toLowerCase() === 'random') { counter += 1; }

if (counter === 5) { document.write("<p>You just win the GOLDEN CROWN!</p>"); } else if(counter === 4 || counter === 3) { document.write("<p>You just win the SILVER CROWN!</p>"); } else if (counter === 2 || counter === 1) { document.write("<p>You just win the BRONCE CROWN!</p>"); } else { document.write("<p>Sorry, you didn't win any crown at all.</p>"); }