Peter has 15 birds. 1/3 are ducks. The rest are chickens and require special feed that costs $2 per bird. How much does it cost to feed the chickens?
2/3 of the birds are chickens because 1 -(1/3)=2/3.
He has 10 chickens because 15 x (2/3) =
<gadget id="calculator">15*(2/3)</gadget>
<output>10</output>
10.
It will cost $20 to feed them because 10 x 2=
<gadget id="calculator">10*2</gadget>
<output>20</output>
20.

<result>20</result>