James buys 20 coins of a cryptocurrency at $15 each.  The value of the coins increases by 2/3.  He sells coins to recoup his original investment.  How many coins did he sell?
His original investment was 15*20=$
<gadget id="calculator">15*20</gadget>
<output>300</output>
300.
The value of his investment increases by 15*2/3=$
<gadget id="calculator">15*2/3</gadget>
<output>10</output>
10 per coin.
So each coin was worth 15+10=$
<gadget id="calculator">15+10</gadget>
<output>25</output>
25.
So he sold 300/25=
<gadget id="calculator">300/25</gadget>
<output>12</output>
12 coins.

<result>12</result>