There are 560 trees planted in Xingfu community, including ginkgo, clove and magnolia, and the ratio of the number of them is 3:2:5. How much less is a ginkgo tree than a magnolia tree?
幸福小区栽种了560棵树，有银杏、丁香和玉兰，它们的棵数比是3：2：5．银杏树比玉兰树少百分之几？
<gadget id="calculator">3 + 2 + 5</gadget>
<output>10</output>

<gadget id="calculator">5 / 10</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">3 / 10</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">(1/2) - (3/10)</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(1/5) / (1/2)</gadget>
<output>2/5 = around 0.4</output>

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

<gadget id="calculator">(2/5) * 1</gadget>
<output>2/5 = around 0.4</output>

<result>2/5 = around 0.4</result>