The toy cabinet in the shopping center bought 80 yo-yos, each priced at 25 yuan, and made a profit of 400 yuan after selling them all. How much is the purchase price of each yo-yo?
购物中心玩具柜购进了80个溜溜球，每个售价25元，全部卖出后赚了400元．每个溜溜球的进价是多少元？
<gadget id="calculator">25 * 80</gadget>
<output>2_000</output>

<gadget id="calculator">2_000 - 400</gadget>
<output>1_600</output>

<gadget id="calculator">1_600 / 80</gadget>
<output>20</output>

<result>20</result>