A livestock farm sells (3/8) of the number of beef cattle, and there are 250 cattle left. How many beef cattle are there in this livestock farm?
一个畜牧场卖出肉牛头数的(3/8)，还剩250头．这个畜牧场原有肉牛多少头？
<gadget id="calculator">3 / 8</gadget>
<output>3/8 = around 0.375</output>

<gadget id="calculator">1 - (3/8)</gadget>
<output>5/8 = around 0.625</output>

<gadget id="calculator">250 / (5/8)</gadget>
<output>400</output>

<result>400</result>