A pair of leather shoes is now sold at 90% of the original price due to seasonal promotions. You can buy this pair of leather shoes at a discount of 15 yuan. Ask for the original price of this pair of leather shoes?
一双皮鞋，现在因换季促销按原价的90%出售，买这双皮鞋可以便宜15元，求这双皮鞋原价？
<gadget id="calculator">90 / 100</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">1 - (9/10)</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">15 / (1/10)</gadget>
<output>150</output>

<result>150</result>