David and Emma are working as a pair to complete a Math Journal. Working alone, David and Emma each needs $$10$$ days and $$18$$ days respectively to complete the journal. In fact, David started to work alone for some days and then handed the work over to Emma. The journal was completed in $$14$$ days altogether. How many days did Emma work on the journal? 
Overseas Competition->Knowledge Point->Word Problem Modules->Equation Word Problems->Word Problems for Linear Equations with One Variable