The original price of a refrigerator was 4088 yuan, after the price was reduced by 250 yuan, the mall earned 180 yuan. How much is the purchase price of this refrigerator?
一台冰箱的原价是4088元，降价250元后，商场还赚了180元．这台冰箱的进价是多少元？
<gadget id="calculator">4_088 - 250 - 180</gadget>
<output>3_658</output>

<result>3_658</result>