With the same amount of money, you can buy 5 fountain pens or 9 ballpoint pens. Each pen is 1.2 yuan more expensive than the ballpoint pen. How much is each pen?
用同样多的钱可以买钢笔5支，或者圆珠笔9支，每支钢笔比圆珠笔贵1.2元，每支钢笔多少元？
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 / 9</gadget>
<output>1/9 = around 0.111111</output>

<gadget id="calculator">(1/5) - (1/9)</gadget>
<output>4/45 = around 0.088889</output>

<gadget id="calculator">1.2 / (4/45)</gadget>
<output>13.5</output>

<gadget id="calculator">13.5 * (1/5)</gadget>
<output>2.7</output>

<result>2.7</result>