20 beavers, working together in a constant pace, can build a dam in 3 hours. How many B hours will it take 12 beavers that work at the same pace, to build the same dam?  Choose the correct choice.
A) 2.  B) 4.  C) B=5.  D) B=6.  E) B=8.
C. 5 hrs   If there were 10 beavers it could have taken double B= 6hrs.. so closest to that option is 5.B=5.
<result>C</result>
20 beavers, working together in a constant pace, can build a dam in 3 hours. How many B hours will it take 12 beavers that work at the same pace, to build the same dam?