Aunt Wang went to buy apples. If she bought 2.5 kilograms, the difference would be 1.6 yuan. If she bought 2 kilograms, it would be 0.9 yuan more. How much money does mother have?
王阿姨去买苹果，如果买2.5千克还差1.6元，如果买2千克则多0.9元，妈妈有多少钱？
<gadget id="calculator">1.6 + 0.9</gadget>
<output>2.5</output>

<gadget id="calculator">2.5 - 2</gadget>
<output>0.5</output>

<gadget id="calculator">2.5 / 0.5</gadget>
<output>5</output>

<gadget id="calculator">5 * 2</gadget>
<output>10</output>

<gadget id="calculator">10 + 0.9</gadget>
<output>10.9</output>

<result>10.9</result>