A store buys a batch of leather sandals, and the selling price of each pair is 15% higher than the purchase price. If you sell all of them, you can make a profit of 120 yuan; how much is the purchase price of this batch of leather sandals? (Hint: What is the relationship between the number of profits per pair and the total number of profits?)
某商店购进一批皮凉鞋，每双售出价比购进价多15%．如果全部卖出，则可获利120元；这批皮凉鞋的购进价是多少元？(提示：每双可获利数，与总获利数有什么关系？)
<gadget id="calculator">15 / 100</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">120 / (3/20)</gadget>
<output>800</output>

<result>800</result>