Sally had some bottled drinks. $$60 \%$$ of the bottled drinks were coffee while the rest were tea. She bought more bottles of tea. In the end, $$40 \%$$ of the bottled drinks were coffee. What was the percentage increase in the number of bottles of tea when more bottles of tea were added to the bottled drinks? 
Overseas Competition->Knowledge Point->Word Problem Modules->Solving Problems Involving Fractions and Percentages->Finding the Rate