For two candles of the same length, it takes 2 hours to light a thick candle, and 1 hour to light a thin candle. One night, there was a power outage. Xiao Fang lit these two candles at the same time to read a book. After a few minutes, the power went off. Fang extinguished the two candles at the same time, and found that the length of the thick candle was twice that of the thin candle. She asked: How long did the power go out for?
两根同样长的蜡烛，点完一根粗蜡烛要2小时，而点完一根细蜡烛要1小时，一天晚上停电，小芳同时点燃了这两根蜡烛看书，若干分钟后来电了，小芳将两支蜡烛同时熄灭，发现粗蜡烛的长是细蜡烛的2倍，问：停电多少分钟？
<gadget id="calculator">2 - 1</gadget>
<output>1</output>

<gadget id="calculator">1 / 60</gadget>
<output>1/60 = around 0.016667</output>

<gadget id="calculator">(1/60) * 2</gadget>
<output>1/30 = around 0.033333</output>

<gadget id="calculator">1 / 120</gadget>
<output>1/120 = around 0.008333</output>

<gadget id="calculator">(1/30) - (1/120)</gadget>
<output>1/40 = around 0.025</output>

<gadget id="calculator">1 / (1/40)</gadget>
<output>40</output>

<result>40</result>