A string $$12$$ meters long is cut into $$6$$ pieces of equal length.  What is the sum of the lengths of any $$4$$ of these pieces? 
Overseas Competition->Knowledge Point->Word Problem Modules->Unitary Method Problems->Finding the Unit Rate and then the Total Value
The string $$12$$ meters long is cut into $$6$$ pieces of length $$2\text{m}$$.  The sum of the lengths of any $$4$$ of these pieces is $$4\times2\text{m}=8\text{m}$$. 