A bakery collected ＄$$1848$$ from selling some pies and cakes. The ratio of money collected from selling the pies to cakes was $$15:7$$. The ratio of the number of pies to cakes sold was $$4 :1$$. A cake cost ＄$$13$$ more than a pie. How many cakes were sold? 
Overseas Competition->Knowledge Point->Word Problem Modules->Solving Problems Involving Fractions and Percentages->Finding the Base