A batch of rice was shipped from the cafeteria, 30% of it was eaten on the first day, and 1/5 was eaten on the second day, leaving 1200 kilograms. How many kilograms of this batch of rice are there?
食堂运来一批大米，第一天吃了30%，第二天吃了(1/5)，还剩下1200千克，这批大米共有多少千克？
<gadget id="calculator">30 / 100</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (3/10) - (1/5)</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1_200 / (1/2)</gadget>
<output>2_400</output>

<result>2_400</result>