Mr. Rainwater has some goats, 9 cows and some chickens. He has 4 times as many goats as cows and 2 times as many goats as chickens. How many chickens does he have?
Let X be the number of chickens Mr. Rainwater has. He has 4 goats/cow * 9 cows = 
<gadget id="calculator">4*9</gadget>
<output>36</output>
36 goats on his farm.
So he has 36 goats / 2 goats/chicken = 
<gadget id="calculator">36/2</gadget>
<output>18</output>
18 chickens.

<result>18</result>