Dongjiao Park originally had 30 cruise ships, with a daily income of 1,200 yuan. According to this calculation, how much can you earn per day if you add 12 more boats? (Solve by two methods of arithmetic and ratio)
东郊公园原有游船30条，每天收入1200元．照这样计算，再增加12条船，每天可收入多少元？(用算数和比例两种方法解答)
<gadget id="calculator">1_200 / 30</gadget>
<output>40</output>

<gadget id="calculator">40 * 30</gadget>
<output>1_200</output>

<gadget id="calculator">40 * 12</gadget>
<output>480</output>

<gadget id="calculator">1_200 + 480</gadget>
<output>1_680</output>

<result>1_680</result>