Xiaolin has 52 yuan. The ratio of the money he used to buy books to the remaining money is 8:5. How much money does he have left?
小林有52元钱，他买书用去的钱数与剩下钱数的比为8：5，他剩下多少元钱．
<gadget id="calculator">8 + 5</gadget>
<output>13</output>

<gadget id="calculator">5 / 13</gadget>
<output>5/13 = around 0.384615</output>

<gadget id="calculator">52 * (5/13)</gadget>
<output>20</output>

<result>20</result>