In May 2008, a charitable organization donated tents to the severely affected Wenchuan area in the Sichuan Earthquake. For the first time, they shipped all tents (3/8) to Wenchuan, and for the second time, they shipped 50 tents. At this time, the number of tents that have been shipped is exactly the number of tents that have not been shipped (5/7). May I ask: How many tents are still not shipped?
2008年5月，某爱心慈善组织向四川大地震中受灾严重的汶川地区捐赠帐篷，他们第一次向汶川运来了全部帐篷的(3/8)，第二次运了50顶帐篷．这时，已运来的帐篷数恰好是没运来的(5/7)，请问：还有多少顶帐篷没有运来？
<gadget id="calculator">3 / 8</gadget>
<output>3/8 = around 0.375</output>

<gadget id="calculator">5 + 7</gadget>
<output>12</output>

<gadget id="calculator">7 / 12</gadget>
<output>7/12 = around 0.583333</output>

<gadget id="calculator">1 - (3/8) - (7/12)</gadget>
<output>1/24 = around 0.041667</output>

<gadget id="calculator">50 / (1/24)</gadget>
<output>1_200</output>

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

<gadget id="calculator">1_200 * (5/8)</gadget>
<output>750</output>

<gadget id="calculator">750 - 50</gadget>
<output>700</output>

<result>700</result>