Xcode older version doesn't get removed properly, after upgrading xcode version from 6.4 to 7.1

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1
  1. I have upgraded Xcode version from 6.4 to Xcode 7.1 version.
  2. I can able to see the Xcode version 7.1 got installed in my system.
  3. When I tried to open Xcode , it doesn’t get opened at all.
  4. When I tried to open simulator also, simulator also doesn’t get opened.
  5. Xcode version of 6.4, doesn’t get deleted properly.
  6. Do anybody, knows solution please help me?
  7. Because of this, I can’t able to inspect in iOS simulator.