A kind of sun visor is priced at 30 yuan after a 40% discount. How much is the original price of this sun visor more expensive than the current price?
一种遮阳帽打六折后的售价是30元，这种遮阳帽原价比现价贵多少元．
<gadget id="calculator">60 / 100</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">30 / (3/5)</gadget>
<output>50</output>

<gadget id="calculator">50 - 30</gadget>
<output>20</output>

<result>20</result>