The ratio of members in the science club to members of the literature club is $$9:10$$. The ratio of members in the literature club to members in the math club is $$5:7$$. Given that all three clubs have a total of $$99$$ members, how many more members are in the math club than the literature club? 
Overseas Competition->Knowledge Point->Word Problem Modules->Solving Problems Involving Proportions->Dividing Quantities Based on Ratio