If a certain brand of TV is sold at a 10% discount, it can make a profit of 120 yuan, and if it is sold at a 15% discount, it will make a loss of 120 yuan. What is the price of the TV set?
某品牌电视机，若9折销售，可盈利120元，若85折销售，就会亏损120元，则电视机的定价是多少元．
<gadget id="calculator">120 + 120</gadget>
<output>240</output>

<gadget id="calculator">90 / 100</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">85 / 100</gadget>
<output>17/20 = around 0.85</output>

<gadget id="calculator">(9/10) - (17/20)</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">240 / (1/20)</gadget>
<output>4_800</output>

<result>4_800</result>