What coould accout for this Toast behavior?

Android Programming (3rd Edition) 2. Android and Model-View-Controller
1

When I run the program I get the following incorrect results. If, for example, in response to “Canberra is the capital of Australia” ( which is True ) I select True, the program correctly pops up the “Correct” toast. However, if I select false as the anaswer to that question, the program also pops up the “Correct” toast. The opposite behavior occurs with respect to questions the answer to which is false. I include the relevant code portions, The Question class and MainActivity ( I named it MainActivity rather than GeoQuiz ) below:

public class Question {
private int mTextResId;
private boolean mAnswerTrue;

public Question(int textResId, boolean answerTrue) {
    mTextResId = textResId;
    mAnswerTrue = answerTrue;
}

public int getTextResId() {
    return mTextResId;
}

public void setTextResId(int textResId) {
    mTextResId = textResId;
}

public boolean isAnswerTrue() {
    return mAnswerTrue;
}

public void setAnswerTrue(boolean answerTrue) {
    mAnswerTrue = answerTrue;
}
}

=-=-=-=-=-=-=-=-=-=

public class MainActivity extends AppCompatActivity {

private Button mTrueButton;
private Button mFalseButton;
private Button mNextButton;
private TextView mQuestionTextView;

private Question[] mQuestionBank = new Question[] {
  new Question(R.string.question_australia, true),
  new Question(R.string.question_oceans, true),
  new Question(R.string.question_mideast, false),
  new Question(R.string.question_africa, false),
  new Question(R.string.question_americas, true),
  new Question(R.string.question_asia, true),
};

private int mCurrentIndex = 0;


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    mTrueButton = (Button) findViewById(R.id.true_button);
    mFalseButton = (Button) findViewById(R.id.false_button);
    mNextButton = (Button) findViewById(R.id.next_button);

    mNextButton.setOnClickListener(new View.OnClickListener(){
        @Override
        public void onClick(View v) {
            mCurrentIndex = (mCurrentIndex + 1) % mQuestionBank.length;
           updateQuestion();
        }
    });

    mTrueButton.setOnClickListener(new View.OnClickListener(){
        @Override
        public void onClick(View v) {
            checkAnswer(true);
        }
    });

    mFalseButton.setOnClickListener(new View.OnClickListener(){
        @Override
        public void onClick(View v) {
           checkAnswer(true);
        }
    });

    mQuestionTextView = (TextView) findViewById(R.id.question_text_view);
    updateQuestion();

}

private void updateQuestion() {
     int question = mQuestionBank[mCurrentIndex].getTextResId();
     mQuestionTextView.setText(question);
}

private void checkAnswer(boolean userPressedTrue){
    boolean answerIsTrue = mQuestionBank[mCurrentIndex].isAnswerTrue();

    int messageResId = 0;

    if(userPressedTrue == answerIsTrue) {
        messageResId = R.string.correct_toast;
    } else {
        messageResId = R.string.incorrect_toast;
    }

    Toast.makeText(this, messageResId, Toast.LENGTH_SHORT).show();
}

}

2

mFalseButton.setOnClickListener(new View.OnClickListener(){
@Override
public void onClick(View v) {
checkAnswer(false);
}
});