title: Ruby array inject
body: <p>I am trying to log the average running time of 10 threads by using the inject method but it's giving me this error:</p>
  
  <pre><code>undefined method `+' for #&lt;Thread:0x10b211590 dead&gt; (NoMethodError)
      from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/open-uri.rb:301:in `inject'
      from client_test.rb:13:in `each'
      from client_test.rb:13:in `inject'
      from client_test.rb:13
  </code></pre>
  
  <p>Here's the code:</p>
  
  <pre><code>require 'open-uri'
  program_start_time = Time.now
  threads = 10.times.map do
    Thread.new do
      time = Time.now
      open('http://ca.yahoo.com/?p=us').read.length
      Time.now-time
    end
  end
  
  threads.map &amp;:join
  puts threads.inject() { |sum, e| sum + e.value}.to_f / threads.size
  puts Time.now - program_start_time
  </code></pre>