A box of apples weighs 30 kilograms. The purchase price per kilogram is 1.56 yuan, and the selling price is 3.44 yuan. How much can you earn by selling them all?
一箱苹果重30千克，每千克进货价格为1.56元，卖出的价格是3.44元，全部卖出去可以赚多少元？
<gadget id="calculator">3.44 - 1.56</gadget>
<output>1.88</output>

<gadget id="calculator">1.88 * 30</gadget>
<output>56.4</output>

<result>56.4</result>