John's cow weighs 400 pounds.  It increased its weight to 1.5 times its starting weight.  He is able to sell the cow for $3 per pound.  How much more is it worth after gaining the weight?
The cow initially weighs 400*1.5=
<gadget id="calculator">400*1.5</gadget>
<output>600</output>
600 pounds.
So it gained 600 - 400 = 
<gadget id="calculator">600-400</gadget>
<output>200</output>
200 pounds.
So its value increased by 200*$3 = $
<gadget id="calculator">200*3</gadget>
<output>600</output>
600.

<result>600</result>