Shopping mall promotion, 15% off the whole site, mom bought a coat and saved 45 yuan, how much is the original price of this coat?
商场促销，全场八五折，妈妈买一件外套节约了45元，这件外套原价多少元？
<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>

<gadget id="calculator">45 / (3/20)</gadget>
<output>300</output>

<result>300</result>