title: How can I find the max value from an array of arrays?
body: <p>I need to find the max value from an array, whose elements are an array, which consists of two elements, first of which is a string representing time and the second an integer. I want the maximum and the minimum values among the second elements of the arrays.</p>
  
  <pre><code>a = [
    ["2015-04-01 20:51:03 +0530", 7],
    ["2015-04-01 20:51:03 +0530", 11],
    ["2015-04-01 20:51:03 +0530", 8],
    ["2015-04-01 20:51:03 +0530", 8],
    ["2015-04-01 20:51:03 +0530", 8],
    ["2015-04-01 20:51:03 +0530", 8],
    ["2015-04-01 20:51:05 +0530", 8],
    ["2015-04-01 20:51:05 +0530", 20],
    ["2015-04-01 20:51:05 +0530", 0],
    ["2015-04-01 20:51:05 +0530", 2],
    ["2015-04-01 20:51:05 +0530", 1],
    ["2015-04-01 20:51:05 +0530", 9]
  ]
  </code></pre>
  
  <p>Any idea what the best way is to do this?</p>