6 week old chicks - gender?

[Miss Chicken]

I'm attempting to purchase two chicks off Craig's List and the poster says he has chicks from a rooster that is a Black Ostralorp and his hens are a mix of Americanas and Silver Laced Wyandots. He says at 6 weeks it's easy to tell male and female apart. Is this true? I HAVE to have hens since I live in the city. I'm worried I'll get a rooster. Thanks for your help!

 

[ve]

If you do not have expiriens is not easy.

 

[Goose and Fig]

You should be able to tell at 6 weeks. If there is any red in the comb, or the comb looks bent-it's a roo. I'm not experienced with the rose comb- but the seller probably is if he has wyandottes.