The price of a set of desks and chairs is 120 yuan, and the price of the chair is the price of the desk (5/7). How much is the price of the chair? Use proportion knowledge to answer.
一套课桌椅的价钱是120元，其中椅子的价钱是课桌的(5/7)，椅子的价钱是多少元？用比例知识解答．
<gadget id="calculator">5 + 7</gadget>
<output>12</output>

<gadget id="calculator">5 / 12</gadget>
<output>5/12 = around 0.416667</output>

<gadget id="calculator">120 * (5/12)</gadget>
<output>50</output>

<result>50</result>