The TV factory's TV output this year is 15% less than last year. This year, 850,000 TV sets were produced. How many TV sets were produced last year?
电视机厂今年电视机的产量比去年减少一成五．今年生产电视机85万台，去年生产电视机多少台？
<gadget id="calculator">15 / 100</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">1 - (3/20)</gadget>
<output>17/20 = around 0.85</output>

<gadget id="calculator">85 / (17/20)</gadget>
<output>100</output>

<result>100</result>