A shopping mall sells two mobile phones with different purchase prices, both of which are sold for 1200 yuan, one of which makes a profit of 50%, and the other loses 20%. In this transaction, how much did the shopping mall earn?
某商场卖出两个进价不同的手机，都卖了1200元，其中一个盈利50%，另一个亏本20%，在这次买卖中，这家商场赚多少元
<gadget id="calculator">50 / 100</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 + (1/2)</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">1_200 / (3/2)</gadget>
<output>800</output>

<gadget id="calculator">1_200 - 800</gadget>
<output>400</output>

<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">1_200 / (4/5)</gadget>
<output>1_500</output>

<gadget id="calculator">1_500 - 1_200</gadget>
<output>300</output>

<gadget id="calculator">400 - 300</gadget>
<output>100</output>

<result>100</result>