title: How to retrieve answers from firestore for a quiz app when we store questions and answers is separate collections?
body: <p>I read on multiple stack overflow posts that we should'nt store questions and answers in Firestore for a quiz app in the same documents. So I created two collections, one represent the questions the other the answers. Here is my firestore architecture:</p>
  <p><a href="https://i.stack.imgur.com/EPhtK.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/EPhtK.png" alt="Question architecture image one" /></a>
  <a href="https://i.stack.imgur.com/nGNne.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/nGNne.png" alt="Question architecture image two" /></a>
  <a href="https://i.stack.imgur.com/mNXy7.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/mNXy7.png" alt="Answer architecture image one" /></a>
  <a href="https://i.stack.imgur.com/E7oD5.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/E7oD5.png" alt="Answer architecture image two" /></a></p>
  <p>When the user clicks on a category the application get 10 questions of a category after the user can click on one answer for each questions. <strong>My problem is how to compare properly the answer the user clicks on with the good answer? I do not want the user to hack my game and know each good answer of all questions.</strong>
  I see two options:</p>
  <ul>
  <li>When the user clicks on an answer, my app send a query to firestore to retrieve the good answer of the question and once the data is loaded it compares with the answer that the users clicked on. I fear this solution because the user needs to wait the data loads when he clicks on the answer.</li>
  <li>The second solution I see is to get all the 10 questions and good answers at the beginning of the game and store all goods answers in a list and retrieve the good answer with the question index. I don't know if the user can hack my app to see all good answers but he will not waits to get the result of his/her choice.</li>
  </ul>