There is a batch of goods in the warehouse, which are shipped out on the first day (1/3), and 400 tons are shipped in on the second day. At this time, the ratio of the goods in the warehouse to the original goods is 3:4. How many tons are shipped out on the first day?
仓库内有一批货物，第一天运出(1/3)，第二天运进400吨，这时仓库内的货物与原来货物的比是3：4，第一天运出货物多少吨？
<gadget id="calculator">3 / 4</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>