The surface of a ball is surrounded by 12 black pentagonal pieces and some white hexagonal pieces. The ratio of black and white pieces is 3:5. How many white pieces are there?
一个皮球的表面是有12块黑色五边形皮和一些白色六边形皮围成的，黑色皮和白色皮的块数比是3：5，白色皮有多少块？
<gadget id="calculator">5 / 3</gadget>
<output>5/3 = around 1.666667</output>

<gadget id="calculator">12 * (5/3)</gadget>
<output>20</output>

<result>20</result>