There are 180 coins with 2 cents and 5 cents, totaling 6 yuan. How many 5 cent coins are there?
有2分和5分的硬币共180枚，一共6元钱．5分的硬币有多少枚．
<gadget id="calculator">6 * 100</gadget>
<output>600</output>

<gadget id="calculator">180 * 2</gadget>
<output>360</output>

<gadget id="calculator">600 - 360</gadget>
<output>240</output>

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

<gadget id="calculator">240 / 3</gadget>
<output>80</output>

<result>80</result>