There are 150 tons of cement in the warehouse, and (1/5) of the total amount is transported away for the first time, and the rest (2/5) is transported away for the second time. How many tons of cement are transported less in the first time than in the second time?
库房有水泥150吨，第一次运走总数的(1/5)，第二次运走余下的(2/5)，第一次比第二次少运走多少吨水泥？
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

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

<gadget id="calculator">(4/5) * (2/5)</gadget>
<output>8/25 = around 0.32</output>

<gadget id="calculator">(8/25) - (1/5)</gadget>
<output>3/25 = around 0.12</output>

<gadget id="calculator">150 * (3/25)</gadget>
<output>18</output>

<result>18</result>