There are two sugar canes, one is 100 cm and the other is 50 cm. After eating a segment of the same length, the short sugar cane becomes a long sugar cane (2/7), then, how many centimeters is a segment of sugar cane?
有两根甘蔗，一根100厘米，一根50厘米，吃掉同样长的一节后，短甘蔗变为长甘蔗的(2/7)，那么，一节甘蔗多少厘米．
<gadget id="calculator">2 / 7</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">100 * (2/7)</gadget>
<output>200/7 = around 28.571429</output>

<gadget id="calculator">50 - (200/7)</gadget>
<output>150/7 = around 21.428571</output>

<gadget id="calculator">1 - (2/7)</gadget>
<output>5/7 = around 0.714286</output>

<gadget id="calculator">(150/7) / (5/7)</gadget>
<output>30</output>

<result>30</result>