There are two types of ticket prices in Oriental Cinema: "3 yuan per ticket" and "4 yuan per ticket". "3 yuan per ticket" has 600 seats, and "4 yuan per ticket" has 300 seats. If all the seats are full, how much can you earn per game?
东方电影院的票价有"每张3元"和"每张4元"两种．"每张3元"的有600个座位，"每张4元"的有300个座位．如果全部坐满，每场能收入多少元？
<gadget id="calculator">3 * 600</gadget>
<output>1_800</output>

<gadget id="calculator">4 * 300</gadget>
<output>1_200</output>

<gadget id="calculator">1_800 + 1_200</gadget>
<output>3_000</output>

<result>3_000</result>