The school buys 20 sets of desks and chairs, and the shared cost is 1040 yuan. It is known that each desk is 40 yuan. How much is each chair?
学校购买20套课桌椅，共用去1040元，已知桌子每张是40元，问椅子每把多少元？
<gadget id="calculator">1_040 / 20</gadget>
<output>52</output>

<gadget id="calculator">52 - 40</gadget>
<output>12</output>

<result>12</result>