title: I cant understand why the need for replacing 'pt' for 'tr', if i don't do it, it doesnt work
body: <pre><code>pt = int(input('First Term: '))
  rz = int(input('Ratio: '))
  tr = pt
  pc = 1
  while pc &lt;= 10:
      print('{}'.format(tr))
      tr += rz
      pc += 1
  </code></pre>
  <p>I cant understand why the  need for replacing 'pt' for 'tr', if i don't do it, it doesnt work</p>