John chops down 30 trees.  From each tree, he can make 25 planks.  A table takes 15 planks to make and sells for $300.  He paid $3000 for all the labor.  How much profit did he make?
He got 30*25=
<gadget id="calculator">30*25</gadget>
<output>750</output>
750 planks.
So he can make 750/15=
<gadget id="calculator">750/15</gadget>
<output>50</output>
50 tables.
That means he makes 50*300=$
<gadget id="calculator">50*300</gadget>
<output>15_000</output>
15000.
So his profit was 15000-3000=$
<gadget id="calculator">15000-3000</gadget>
<output>12_000</output>
12000.

<result>12_000</result>