A certain chicken farm sells a batch of broilers, 40% of the total broiler chickens are sold for the first time, and the remaining 50% is sold for the second time. At this time, there are still 1,200 broilers in the chicken farm. How many broilers did the chicken farm have?
某鸡场卖出一批肉鸡，第一次卖出肉鸡总量的40%，第二次卖出剩下的50%，这时鸡场还有1200只，鸡场原有肉鸡多少只？
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (2/5)</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">50 / 100</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(3/5) * (1/2)</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">1 - (2/5) - (3/10)</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">120 / (3/10)</gadget>
<output>400</output>

<result>400</result>