Sensen spent 15 yuan to buy 3 pens, and the price of a stationery bag is 2 times more than 1 pen, how much does it cost to buy a stationery bag?
森森买3支钢笔花了15元，一个文具袋的价格是1支钢笔的2倍多2元，买一个文具袋需要多少钱？
<gadget id="calculator">15 / 3</gadget>
<output>5</output>

<gadget id="calculator">5 * 2</gadget>
<output>10</output>

<gadget id="calculator">10 + 2</gadget>
<output>12</output>

<result>12</result>