Linda paid $$8$$ dollars for $$4$$ potatoes. How many dollars did Linda pay for the same kind of potatoes if she bought $$6$$ more of them? (adapted from $$2008$$ Math kangaroo Problems, Level $$1-2$$, Question \#$$13$$) 
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Linda paid ＄$$8$$ for $$4$$ potatoes, $$8\div4=2$$, so we can know $$1$$ potatoes cost $$2$$ dollars. In total Linda should pay $$2\times10=20$$ dollars for $$10$$ potatoes. 