Xiaoming's mother bought 2.5kg of apples and 3.2kg of lychees, each kilogram of apples was 2.8 yuan, and each kilogram of lychees was 7.7 yuan more expensive than each kilogram of apples. How much does mother have to pay in total?
小明的妈妈买了2.5千克苹果和3.2千克荔枝，每千克苹果2.8元，每千克荔枝比每千克苹果贵7.7元．妈妈一共要付多少元？
<gadget id="calculator">2.5 * 2.8</gadget>
<output>7</output>

<gadget id="calculator">2.8 + 7.7</gadget>
<output>10.5</output>

<gadget id="calculator">3.2 * 10.5</gadget>
<output>33.6</output>

<gadget id="calculator">7 + 33.6</gadget>
<output>40.6</output>

<result>40.6</result>