If you looked at the options you would have noticed that some show five pairs and others show the ten. That is what it means by 5/10. If you select a five pair then you are getting five pairs. If you select a ten pair set you will get ten pairs. These are great socks, I would definitely recommend.
Sometimes the post man said it delivered but they will deliver it the next day or sent to your neighbors address especially a duplex house. If nothing shows up , you can contact amazon customer service through chat. And they respond to you right away.
I think their description is not accurate. they're just right for me, BUT I would not consider them thick or athletic. They're definitely thicker than a dress sock but not as thick as a traditional athletic crew sock.