The output in January is 85% of the output in February, so how much less is the output in January than in February?
一月份产量是二月份产量的85%，那么一月份产量比二月份少多少
<gadget id="calculator">85 / 100</gadget>
<output>17/20 = around 0.85</output>

<gadget id="calculator">1 - (17/20)</gadget>
<output>3/20 = around 0.15</output>

<result>3/20 = around 0.15</result>