The fruit wholesale station, on the first day, the wholesale fruit is half of the stock and less than 20 boxes, on the second day, the remaining half is more than 30 boxes, and on the third day, 200 boxes are shipped in, which doubles the fruit in the warehouse How many boxes?
水果批发站，第一天批发水果是库存的一半少20箱，第二天又批出剩余的一半多30箱，第三天运进200箱，使库里的水果增加2倍，原有水果多少箱？
<gadget id="calculator">200 / 2</gadget>
<output>100</output>

<gadget id="calculator">100 + 30</gadget>
<output>130</output>

<gadget id="calculator">130 * 2</gadget>
<output>260</output>

<gadget id="calculator">260 - 20</gadget>
<output>240</output>

<gadget id="calculator">240 * 2</gadget>
<output>480</output>

<result>480</result>