The two warehouses of A and B have a total of 1200 tons of fertilizers. Now transport (3/8) from warehouse A to warehouse B. At this time, the ratio of fertilizers in warehouses A and B is 5:7. How many tons of fertilizers does Warehouse B have?
甲乙两个仓库共有化肥1200吨．现从甲仓库中运(3/8)到乙仓库，这时甲乙两仓库的化肥数的比是5：7．原来乙仓库有化肥多少吨？
<gadget id="calculator">5 + 7</gadget>
<output>12</output>

<gadget id="calculator">1_200 / 12</gadget>
<output>100</output>

<gadget id="calculator">100 * 5</gadget>
<output>500</output>

<gadget id="calculator">3 / 8</gadget>
<output>3/8 = around 0.375</output>

<gadget id="calculator">1 - (3/8)</gadget>
<output>5/8 = around 0.625</output>

<gadget id="calculator">500 / (5/8)</gadget>
<output>800</output>

<gadget id="calculator">1_200 - 800</gadget>
<output>400</output>

<result>400</result>