Mom bought a desk with a 30% discount, and saved 120 yuan after the discount. How much is the original price of this desk?
妈妈买了一个打7折出售的书桌，打折后节约了120元，这张书桌的原价是多少元？
<gadget id="calculator">70 / 100</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">1 - (7/10)</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">120 / (3/10)</gadget>
<output>400</output>

<result>400</result>