20 beavers, working together in a constant pace, can build a dam in 3 hours. How many hours Z will it take 12 beavers that work at the same pace, to build the same dam?
Choose one.
A) 2 .	B) z = 4 .	C) z = 5 .	D) 6 .	E) 8 .

Rationale: "c . 5 hrs if there were 10 beavers it qould have taken double z = 6 hrs . . so closest to that option is 5 ."
Answer: C