private int score = 0;
…
private void checkAnswer(boolean pickedAnswer) {
    boolean correctAnswer = allQuestions.list.get(questionNumber).answer;
    if (correctAnswer == pickedAnswer) {
        score = score + 1;
        …
    } else {
       …
    }
    …
}
…
private void nextQuestion() {
    if (questionNumber <= allQuestions.list.size() - 1) {
        tvQuestion.setText(allQuestions.list.get(questionNumber).questionText);
        tvQuestionNumber.setText(questionNumber  + 1 + “/“ + allQuestions.list.size( ));
        tvScore.setText(“Score: “ + score);
    } else { …         }
}