The area of a piece of land is about (3/4) hectares, of which (1/4) is planted with roses, (2/5) is planted with tulips, and the rest is planted with rhododendrons, and the area planted with rhododendrons accounts for a fraction of the total area ?
一块地的面积约(3/4)公顷，其中(1/4)的种玫瑰花，(2/5)种郁金香，其余部分种杜鹃花，种杜鹃花的面积占总面积的几分之几？
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

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

<gadget id="calculator">1 - (1/4) - (2/5)</gadget>
<output>7/20 = around 0.35</output>

<result>7/20 = around 0.35</result>