How to set Attribute for certain quantity of one product?

[allright]

Hi all,

 

For example, I have 30 T-shirts(same product name), and 10 in different sizes: L, M, S respectively.

 

How to set the product attribute like the following quantity:

*10 T-shirts in Size L;

*10 T-shirts in Size M;

*10 T-shirts in Size S;

 

I could not find the quantity definition for attribute setting in the admin, please kindly advise, thank you.

 

Best regards,

allright