There is a batch of goods in the warehouse. (1/3) of this batch of goods was shipped out on the first day, and 400 tons were shipped in on the second day. At this time, the goods in the warehouse were exactly 75% of the original volume. How many tons were shipped out on the first day?
仓库内有一批货物，第一天运出这批货物的(1/3)，第二天运进400吨，这时仓库的货物正好是原来的75%，第一天运出多少吨？
<gadget id="calculator">75 / 100</gadget>
<output>3/4 = around 0.75</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">(3/4) - (2/3)</gadget>
<output>1/12 = around 0.083333</output>

<gadget id="calculator">400 / (1/12)</gadget>
<output>4_800</output>

<gadget id="calculator">4_800 * (1/3)</gadget>
<output>1_600</output>

<result>1_600</result>