Luk Fook Chicken Farm sold a batch of broilers, 40% of the total number of broilers were sold for the first time, and 1/3 of the total number of broilers were sold for the second time. There are still 1,200 broilers left. How many broilers are there in total? (solution by equation)
六福鸡场卖出一批肉鸡，第一次卖出肉鸡总数的40%，第二次卖出肉鸡总数的(1/3)，还剩肉鸡1200只，鸡场有肉鸡共多少只？(用方程解)
<gadget id="calculator">40 / 100</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>