avoiding queries in loops for gradebook - php

Question

I am making a gradebook and while the code below works, it is awfully slow. The first Column for the table is each students name, and then each cell afterwords corresponds to a specific question and shows what the students answer was. Not each student will have answered the given question.
Right now I have a loop and for each user a loop inside of that loop for each question.
Each question has a unique id, in a separate table each answer has a corresponding user id and a corresponding question id.
I have looked for similar posts with no luck, I have only been working with php for a few months so any advice will be much appreciated.
Questions
| id | question | choice 1 | choice 2 | choice 3 | choice 4 | correctAnswer | categoryId |
Answers
| id | questionId | userId | studentAnswer |
Users
| id | firstName |
Thanks
//Select all questions from a specific category $mid defined by user
$questionQuery = mysql_query("SELECT * FROM questions WHERE mid = $mid");
$questionCount = mysql_num_rows($questionQuery);
//Blank space in table above users
echo "<tr><td></td>";
//Question Number, each category has a different number of questions
for ($q = 0; $q < $questionCount; $q++){
echo "<td>" . ($q+1) . "</td>";
}
echo "</tr>";
//Select all students for a given teacher
$userQuery = mysql_query("SELECT * FROM users WHERE teacherId = $userid ORDER BY `block`, `lastName`");
$userCount = mysql_num_rows($userQuery);
for($s = 0; $s < $userCount; $s++){
$currentUserId = mysql_result($userQuery, $s, 0);
//Echo student's name
echo "<tr class='user" . ($s%2) ."'><td>" . mysql_result($userQuery, $s, 1) . "</td>";
//Load current question id
for ($q = 0; $q < $questionCount; $q++){
$questionNum = mysql_result($questionQuery, $q, 0);
//Selects students answer from answers database for above question
$answerQuery = mysql_query("SElECT * FROM answers WHERE questionId = $questionNum AND userId = $currentUserId");
$answerCount = mysql_num_rows($answerQuery);
//If no answers move on to next cell
if($answerCount == 0){
echo "<td></td>";
}
else{
$currentAnswer = mysql_result($answerQuery, 0, 3);
$correctAnswer = mysql_result($questionQuery, $q, 6);
if ($currentAnswer == $correctAnswer){
echo "<td class='right'><div id='parent'>" . $currentAnswer . "</div></td>";
}
else{
echo "<td class='wrong'><div id='parent'>" . $currentAnswer . "</div></td>";
}
}
}
echo "</tr>";
}