It costs Xiao Qiao 19 yuan to buy 1 fountain pen and 3 ballpoint pens. If she buys one less ballpoint pen, it only costs 17 yuan. How much is each pen?
小巧买1支钢笔和3支圆珠笔共需19元，如果她少买一支圆珠笔就只需17元，每支钢笔多少钱？
<gadget id="calculator">19 - 17</gadget>
<output>2</output>

<gadget id="calculator">2 * 3</gadget>
<output>6</output>

<gadget id="calculator">19 - 6</gadget>
<output>13</output>

<result>13</result>