The number of bicycles sold in a store accounts for (3/7) of the total, and there are 1200 bicycles left. How many bicycles does this store have?
一商店卖出的自行车占总数的(3/7)，还剩1200辆，这间商店原有自行车有多少辆．
<gadget id="calculator">3 / 7</gadget>
<output>3/7 = around 0.428571</output>

<gadget id="calculator">1 - (3/7)</gadget>
<output>4/7 = around 0.571429</output>

<gadget id="calculator">1_200 / (4/7)</gadget>
<output>2_100</output>

<result>2_100</result>