A desk is 280 yuan, which is 19 yuan cheaper than the total price of 13 chairs. How much does a chair cost? (List the answers to the comprehensive formula.)
一张办公桌280元，比13把椅子的总价钱便宜19元．一把椅子的价钱是多少元？(列综合算式解答．)
<gadget id="calculator">280 + 19</gadget>
<output>299</output>

<gadget id="calculator">299 / 13</gadget>
<output>23</output>

<result>23</result>