A bottle of alcohol, pour out (1/3) for the first time, then pour 40 grams back into the bottle, pour out the rest of the alcohol for the second time (5/9), pour out 180 grams for the third time, and there is still left in the bottle Under 60 grams, how many grams of alcohol are in the original bottle.
一瓶酒精，第一次倒出(1/3)，然后倒回瓶中40克，第二次到出剩下酒精的(5/9)，第三次倒出180克，瓶中还剩下60克，原来瓶中有酒精多少克．
<gadget id="calculator">180 + 60</gadget>
<output>240</output>

<gadget id="calculator">5 / 9</gadget>
<output>5/9 = around 0.555556</output>

<gadget id="calculator">1 - (5/9)</gadget>
<output>4/9 = around 0.444444</output>

<gadget id="calculator">240 / (4/9)</gadget>
<output>540</output>

<gadget id="calculator">540 - 40</gadget>
<output>500</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 - (1/3)</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">500 / (2/3)</gadget>
<output>750</output>

<result>750</result>