A set of tables and chairs is 120 yuan, and the price of the chairs is the price of the table (5/7). How much is each table more expensive than the chairs?
一套桌椅120元，椅子价格是桌子的(5/7)，每个桌子比椅子贵多少元？
<gadget id="calculator">5 / 7</gadget>
<output>5/7 = around 0.714286</output>

<gadget id="calculator">1 + (5/7)</gadget>
<output>12/7 = around 1.714286</output>

<gadget id="calculator">120 / (12/7)</gadget>
<output>70</output>

<gadget id="calculator">120 - 70</gadget>
<output>50</output>

<gadget id="calculator">70 - 50</gadget>
<output>20</output>

<result>20</result>