Error during installation

TASK [mariadb : Update apt cache] **********************************************
fatal: [localhost]: FAILED! => {“changed”: false, “failed”: true, “msg”: “Failed to update apt cache.”}

I am getting these error on Ubuntu 14.

Please suggest me.

what’s the output for sudo apt-get update

W: Failed to fetch 404 Not Found

Have you installed mariadb 5.5 separately?

No, I have not installed