A person bought a lottery ticket and won a big prize, and paid 20% of the personal income tax according to the regulations. He then drew 100,000 yuan from the bonus to subsidize the disaster area, and there was still 120,000 yuan left. May I ask how much this person won the lottery this time?
某人购买彩票中了大奖，按规定缴纳20%的个人所得税，他又从奖金中抽出10万元资助灾区，这时还余下12万元．请问此人这次中奖的金额是多少万元？
<gadget id="calculator">10 + 12</gadget>
<output>22</output>

<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">22 / (4/5)</gadget>
<output>55/2 = around 27.5</output>

<result>55/2 = around 27.5</result>