A repeater is 280 yuan, and the price of a TV is 50 yuan more than three times that. How much is a TV set?
一台复读机280元，一台电视机的价钱比它的3倍还多50元．一台电视机多少元？
<gadget id="calculator">280 * 3</gadget>
<output>840</output>

<gadget id="calculator">840 + 50</gadget>
<output>890</output>

<result>890</result>