Anna, Betsy and Chariene had a tolal of $$168$$ marbles. Charlano gave $$15$$ marbles to Betsy. Then, Batsy gave $$8$$ marbles to Anna. In tho end, tho ratio of the number of marbles that Anna had to the numbor of marblas that Betsy had to the number of marbles that Charlene had is $$2:5:7$$. How many marbles did Betsy have at first? 
Overseas Competition->Knowledge Point->Word Problem Modules->Solving Problems Involving Proportions->Dividing Quantities Based on Ratio