$question = new Question();
$answer = new Answer();
foreach ($request->get('questions') as $idnex => $question) {
    $question->book_id = $request->get('bookId');
    $question->question = $question;
    $question->save();
    foreach ($request->get('answers') as $idnex => $answer) {
        $answer->answer = $answer;
        $answer->question_id = $question->id;
        if ($request->has("isCorrect[{$index}]")) {
            $answer->is_correct = 1;
        } else {
            $answer->is_correct = 0;
        }
    }
}