Failed in use apt-get and yum into container

Good afeternoon.

I Have one trouble in utilizing the command below:

docker run -ti –name teste ubuntu

When the container is created and i use the command apt-get or yum appear the message:

root@*******:/# apt-get install nginx
Reading package lists… Done
Building dependency tree
Reading state information… Done
E: Unable to locate package nginx


root@*******:/# apt-get update
0% [Connecting to]

I need help with this problem, please help me.