For a park, adult tickets are 5 yuan each; child tickets are 2.5 yuan each. Mom and Dad took Xiaoling and her classmates to the park. How much does it cost to buy tickets?
一个公园，成人票每张5元；儿童票每张2.5元．爸爸、妈妈带着小玲和同学去逛公园，买门票一共需要多少钱？
<gadget id="calculator">5 * 2</gadget>
<output>10</output>

<gadget id="calculator">2.5 * 2</gadget>
<output>5</output>

<gadget id="calculator">10 + 5</gadget>
<output>15</output>

<result>15</result>