There is a garden of 680 square meters in Zhou Enlai's Red Army Elementary School plan, in which (1/4) are planned to be azaleas, (1/5) are to be planted with roses, and the rest are to be planted with lawns. What percentage of the area is the lawn?
周恩来红军小学的规划图中有一块680平方米的花园，计划其中的(1/4)种杜鹃花，其中的(1/5)种月季花，其余种草坪．草坪的面积占几分之几？
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/4) - (1/5)</gadget>
<output>11/20 = around 0.55</output>

<result>11/20 = around 0.55</result>