The factory has 120 tons of cement, which is shipped out (1/4) on the first day and (2/5) on the second day. How many tons more are shipped out on the second day than on the first day?
工厂有水泥120吨，第一天运出(1/4)，第二天运出(2/5)，第二天比第一天多运出多少吨？
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(2/5) - (1/4)</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">120 * (3/20)</gadget>
<output>18</output>

<result>18</result>