There is a batch of grain at a certain grain station. After transporting (1/5), another 30 kg is transported, which is 10% less than the original. How many kilograms of grain did this grain station have?
某粮站有一批粮食，运走(1/5)后，又运来30千克，这时比原来少10%．这个粮站原有粮食多少千克？
<gadget id="calculator">90 / 100</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">(9/10) - (4/5)</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">30 / (1/10)</gadget>
<output>300</output>

<result>300</result>