Sunshine Store increased the purchase price of DVDs by 55%, and later advertised "20% discount for guests, free 30 yuan taxi fare". As a result, each DVD still made a profit of 210 yuan. So how much is the purchase price of each DVD?
阳光商店将DVD按进价提高55%，以后"八折酬宾，外送30元出租车费"的广告，结果每台DVD仍获利210元．那么每台DVD的进价是多少元？
<gadget id="calculator">210 + 30</gadget>
<output>240</output>

<gadget id="calculator">55 / 100</gadget>
<output>11/20 = around 0.55</output>

<gadget id="calculator">1 + (11/20)</gadget>
<output>31/20 = around 1.55</output>

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

<gadget id="calculator">(31/20) * (4/5)</gadget>
<output>31/25 = around 1.24</output>

<gadget id="calculator">(31/25) - 1</gadget>
<output>6/25 = around 0.24</output>

<gadget id="calculator">240 / (6/25)</gadget>
<output>1_000</output>

<result>1_000</result>