The actual investment is 15% less than the planned investment, and the actual investment is the planned investment.
实际投资比计划投资节约15%，实际投资是计划投资的多少．
<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>

<result>17/20 = around 0.85</result>