There are 3 tons of chemical fertilizers, transported away (1/4) on the first day, and transported away (2/5) on the second day, how many tons are transported?
有3吨化肥，第一天运走(1/4)，第二天运走(2/5)，运走多少吨？
<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">(1/4) + (2/5)</gadget>
<output>13/20 = around 0.65</output>

<gadget id="calculator">3 * (13/20)</gadget>
<output>39/20 = around 1.95</output>

<result>39/20 = around 1.95</result>