$$David\textquotesingle s$$ cookies were cost thrice as much as $$Jeremy\textquotesingle s$$ cookies. $$David$$ had only $$$0.50$$ cookies while $$Jeremy$$ had~$\tfrac{3}{5}$~as many $$$0.50$$ cookies as $$$0.10$$ cookies. There were $$60$$ fewer $$$0.10$$ cookies than $$$0.50$$ cookies. How much were $$Jeremy\textquotesingle s$$ cookies worth? 
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