There are 55 desks in the classroom, Lan Lan wiped all the desks (3/5), obviously wiped all the desks (2/5). Clearly, how many desks were wiped less than Lan Lan?
教室里有55张课桌，兰兰擦了全部课桌的了(3/5)，明明擦了全部课桌的(2/5)．明明比兰兰少擦几张课桌？
<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

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

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

<gadget id="calculator">55 * (1/5)</gadget>
<output>11</output>

<result>11</result>