If a newly-launched Apple ipad2 is sold at 20% off the original price, it can make a profit of 100 yuan, and if it is sold at 50% off the original price, it can make a profit of 700 yuan. What is the purchase price of this Apple ipad2?
一台新上市的苹果ipad2如果按原价的八折出售可获利100元，如果按原价的九五折出售可获利700元，那么这台苹果ipad2的进货价格是多少元
<gadget id="calculator">700 - 100</gadget>
<output>600</output>

<gadget id="calculator">95 / 100</gadget>
<output>19/20 = around 0.95</output>

<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">(19/20) - (4/5)</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">600 / (3/20)</gadget>
<output>4_000</output>

<gadget id="calculator">4_000 * (4/5)</gadget>
<output>3_200</output>

<gadget id="calculator">3_200 - 100</gadget>
<output>3_100</output>

<result>3_100</result>