There are 50 goldfish in the pond. Each goldfish eats 1.5 ounces of food per day. 20% of the goldfish need to eat special food that costs $3 an ounce. How much does it cost to feed these fish?
There are 10 fish who need the special food because 50 x .2 = 
<gadget id="calculator">50*.2</gadget>
<output>10</output>
10.
These fish eat 15 ounces a day because 10 x 1.5 = 
<gadget id="calculator">10*1.5</gadget>
<output>15</output>
15.
This food costs $45 because 15 x 3 = 
<gadget id="calculator">15*3</gadget>
<output>45</output>
45.

<result>45</result>