Cup A contains $$300\text{mL}$$ of $$20 \%$$ sugar water and Cup B contains $$300\text{mL}$$ of $$30 \%$$ sugar water. If I mix the sugar water in the two cups well, what is the sugar concentration of the mixture I get?      Pip\textquotesingle s answer: $$20 \%+30 \%=50 \%$$ 
Overseas Competition->Knowledge Point->Word Problem Modules->Concentration Problems