15 beavers, working together in a constant pace, can build a dam in 4 hours. how many hours will it take 20 beavers that work at the same pace, to build the same dam?  Choose the correct choice.
A) 2 .  B) 4 .  C) 5 .  D) 6  E) 3 .
<gadget id="calculator">4 * 15</gadget>
<output>60</output>

<gadget id="calculator">60 / 20</gadget>
<output>3</output>

<result>E</result>
15 beavers, working together in a constant pace, can build a dam in 4 hours. how many hours will it take 20 beavers that work at the same pace, to build the same dam?
divide(multiply(4, 15), 20)
"total work = 15 * 4 = 60 beaver hours 20 beaver * x = 60 beaver hours x = 60 / 20 = 3 answer : e"