There is a pen in a stationery store, and it costs 20 yuan to buy 3 pens; if you buy 6 pens like this, how much will it cost in total?
文具店有一种钢笔，买3支要20元；如果买这样的6支钢笔，一共要多少钱？
<gadget id="calculator">6 / 3</gadget>
<output>2</output>

<gadget id="calculator">20 * 2</gadget>
<output>40</output>

<result>40</result>