How to use ActiveRecord associations to select from related.

table "users" [Stores user information]
id, username, password,email

table "exams" [Stores exam information]
id, name, description

table "questions" [stores question information]
id, question, opt1, opt2, opt3,opt4, correct

table "exam_questions" [stores selection of questions for a particular
exam or test]
id, exam_id, question_id

table "user_answers" [stores the user response to the questions in exam]
id, user_id,exam_id,question_id,userans, created_at

Associations in my models:

"user.rb"
  has_many :user_answers

"exam.rb"
  has_many :exam_questions
  has_many :questions, :through=>:exam_questions
  has_many :user_answers

"question.rb"
  has_many :exam_questions
  has_many :exams, :through=>:exam_questions
  has_many :user_answers

"exam_question.rb"
  belongs_to :exam
  belongs_to :question

"user_answer.rb"
  belongs_to :user
  belongs_to :question
  belongs_to :exam

Now what I need is:
1. To extract the exam and question details by running a query in
ExamQuestion table. Is this possible?
   something like: @detail=ExamQuestion.find(:all) and then looping also
displaying the question and exam detail. I don't want to use find_by_sql

2. Also to extract form UserAnswer table and display the exam detail,
question detail and user answer with a single hit in database.

In general terms, I want to use the features of Active Record
associations to run a query to extract as much informaton as possible
from multiple tables.
This is to avoid multiple queries.
Please help.

Please help me by responding to the above post.

Your help will be appreciated.

Thanks