Generally, yes it is true that store brands are cheaper than national brands. This is because they are often copies of existing brands using lower quality packaging/products.
I believe that is the age of sixteen.
Vietnam was the first Asian state and the second in the world to ratify the United Nations Convention on the Rights of the Child in 1990. In addition, the Law on child protection, care and education was ratified by the National Assembly in 1991; this Law was then amended in 2004. Since then, Vietnam has issued 22 laws and legislative documents regarding the rights of children. The Prime Minister approved two important national programs in 2011, including the National Program on Child Protection and the National Plan of Actions for Children. I hope this helps!!