In a class, there are 25 people who like Chinese, 30 people who like mathematics, and 10 people who like both subjects. How many people are there in this class?
某班喜欢语文学科的有25人，喜欢数学学科的有30人，两门学科都喜欢的有10人，这个班共有多少人．
<gadget id="calculator">30 - 10</gadget>
<output>20</output>

<gadget id="calculator">25 + 20</gadget>
<output>45</output>

<result>45</result>