There are 18 coins with 2 cents and 5 cents, totaling 6 dimes. How many 5 cent coins are there?
有2分和5分的硬币共18枚，一共6角钱．5分的硬币有多少枚．
<gadget id="calculator">6 * 10</gadget>
<output>60</output>

<gadget id="calculator">18 * 2</gadget>
<output>36</output>

<gadget id="calculator">60 - 36</gadget>
<output>24</output>

<gadget id="calculator">5 - 2</gadget>
<output>3</output>

<gadget id="calculator">24 / 3</gadget>
<output>8</output>

<result>8</result>