A kind of U disk, each price has been reduced from 400 yuan to 250 yuan, how much has the price of this U disk been reduced?
一种U盘，每个从400元降价到250元，这种U盘降价了多少
<gadget id="calculator">400 - 250</gadget>
<output>150</output>

<gadget id="calculator">150 / 400</gadget>
<output>3/8 = around 0.375</output>

<result>3/8 = around 0.375</result>