The agricultural material company sells (2/5) of the original chemical fertilizer, and ships in another 1,200 tons. At this time, the stored chemical fertilizer is exactly (2/3) of the original chemical fertilizer. How many tons of the original chemical fertilizer does this company have?
农资公司出售原有化肥的(2/5)，又运来1200吨，这时存化肥恰好是原有化肥的(2/3)，这个公司原有化肥多少吨？
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">(2/3) - 1</gadget>
<output>-1/3 = around -0.333333</output>

<gadget id="calculator">(2/5) + (-1/3)</gadget>
<output>1/15 = around 0.066667</output>

<gadget id="calculator">1_200 / (1/15)</gadget>
<output>18_000</output>

<result>18_000</result>