In order to reward students who actively participated in mathematics extracurricular activities, the class committee went to buy prizes. They bought 25 prizes for 1.8 yuan and 15 prizes for 2.5 yuan. How much did it cost to buy these two prizes?
为了奖励积极参加数学课外活动的同学，班委去买奖品，1.8元的奖品买了25份，2.5元的奖品买了15份．买这两种奖品一共花去多少钱？
<gadget id="calculator">1.8 * 25</gadget>
<output>45</output>

<gadget id="calculator">2.5 * 15</gadget>
<output>37.5</output>

<gadget id="calculator">45 + 37.5</gadget>
<output>82.5</output>

<result>82.5</result>