During the 2010 World Expo, a supermarket purchased a batch of Haibao, and the actual selling price was 3.5 times the cost. According to this pricing, what is the profit margin?
2010世博会期间，某超市购进了一批海宝，实际卖的价格是成本的3.5倍，按照这个定价，利润率是多少
<gadget id="calculator">1 * 3.5</gadget>
<output>3.5</output>

<gadget id="calculator">3.5 - 1</gadget>
<output>2.5</output>

<gadget id="calculator">2.5 / 1</gadget>
<output>2.5</output>

<gadget id="calculator">100 / 100</gadget>
<output>1</output>

<gadget id="calculator">2.5 * 1</gadget>
<output>2.5</output>

<result>2.5</result>