Put some white balls and red balls in a box, among which 5 red balls account for (1/10) of the total number, and how many red balls are put in so that the red balls account for (1/6) of the total number.
一个盒子里放了一些白球和红球，其中5个红球，占总数的(1/10)，再放进多少个红球，可以使红球占到总数的(1/6)．
<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">5 / (1/10)</gadget>
<output>50</output>

<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">50 * (1/6)</gadget>
<output>25/3 = around 8.333333</output>

<gadget id="calculator">(25/3) - 5</gadget>
<output>10/3 = around 3.333333</output>

<gadget id="calculator">1 - (1/6)</gadget>
<output>5/6 = around 0.833333</output>

<gadget id="calculator">(10/3) / (5/6)</gadget>
<output>4</output>

<result>4</result>