A sporting goods store bought a batch of basketballs, divided into first-class products and second-class products. The purchase price of the second-class products is 25% cheaper than that of the first-class products. According to the principle of high quality and high price, the first-class products are priced at a profit margin of 20%. , The second-grade product is priced at a profit margin of 10%. The first-grade basketball is 18 yuan more expensive than the second-grade basketball. Q: What is the purchase price of the first-grade basketball?
某体育用品商店进了一批篮球，分一级品和二级品，二级品的进价比一级品便宜25%，按优质优价的原则，一级品按20%的利润率定价，二级品按10%的利润率定价，一级品篮球比二级品篮球每个贵18元，问：一级品篮球的进价是每个多少元．
<gadget id="calculator">1.2 - 0.825</gadget>
<output>0.375</output>

<gadget id="calculator">18 / 0.375</gadget>
<output>48</output>

<result>48</result>