Anaconda libstdc++.so.6: version `GLIBCXX_3.4.20' not found

I am using anaconda for python and I face this problem I tried a lot to solve this error, but still not solved.

I used the following commands so far

sudo apt-get install libstdc++6
sudo add-apt-repository ppa:ubuntu-toolchain-r/test 
sudo apt-get update
sudo apt-get upgrade
sudo apt-get dist-upgrade

conda install libgcc

in this link a solution provided but I still don't know how to do that


I solved this by

conda install libgcc=5.2.0

A solution that worked for me was:

conda install -c anaconda libstdcxx-ng