Why is my if statement always evaluating true?

/*Questions
1. What is my name - Mike
2. How old am I - 29
3. Where was I Born - Cardiff
*/

var questions = [
                ["What is my name?","Mike"],
                ["How old am I?","29"],
                ["Where Was I born?","Cardiff"]
                ];
var score=0;

//arrays of integers representing the index in questions of the correct / incorrect questions
var incorrect=[];
var correct=[];

var i=0;
do {

var answer=prompt(questions[i][0]);
var questionAnswer=questions[i][1];
  if (answer.toLowerCase === questionAnswer.toLowerCase) {

    //correct
    console.log("correct "+questions[i][1]+"-"+answer);
    score+=1;
    correct.push(i);

  }else {

    incorrect.push(i);

  }

i+=1;  
}while(i<questions.length)