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