The original price of a piece of clothing is 120 yuan, but now it is sold at a 25% discount. How much is it cheaper to buy this dress?
一件衣服原价120元，现在按七五折出售，买这件衣服便宜了多少元？
<gadget id="calculator">75 / 100</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">120 * (3/4)</gadget>
<output>90</output>

<gadget id="calculator">120 - 90</gadget>
<output>30</output>

<result>30</result>