$$Amelia$$ had $$160$$ cookies and $$Bala$$ had $$320$$ more cookies than $$Daniel$$. $$Bala$$ had~$\tfrac{1}{2}$~as many cookies as $$Amelia$$, $$Carl$$ and $$Daniel$$. $$Carl$$ had~$\tfrac{3}{4}$~as many cookies as $$Amelia$$, $$Bala$$ and $$Daniel$$. They had $$6230$$ cookies in total. How many cookies did $$Daniel$$ have? 
Overseas Competition->Knowledge Point->Combinatorics->Patterns of Figures->Change of Quantity