A barrel of gasoline weighs 75 kilograms, how many kilograms are left after (2/5) is used up?
一桶汽油重75千克，用去(2/5)后，还剩多少千克．
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (2/5)</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">75 * (3/5)</gadget>
<output>45</output>

<result>45</result>