Let a, b be the number of 3-ounce packages and 10-ounce packages B-Rite sold 

\(\left\{{}\begin{matrix}3a+10b< 16.16\\a+b=76\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}3a+3b+7b< 256\\3a+3b=228\end{matrix}\right.\)

\(\Rightarrow7b< 28\Rightarrow b< 4\)

So, the answer is 3