A chicken farm sells (2/5) of the total number of chickens on the first day, and sells (1/3) of the total number of chickens on the second day, leaving 1200 chickens. How many chickens are there in total?
某鸡场第一天卖出养鸡总只数的(2/5)，第二天卖出养鸡总数的(1/3)，还剩1200只鸡，养鸡场共养鸡多少只？
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 - (2/5) - (1/3)</gadget>
<output>4/15 = around 0.266667</output>

<gadget id="calculator">1_200 / (4/15)</gadget>
<output>4_500</output>

<result>4_500</result>