Xiaohua surveyed 40 students in the sports team, 25 of them like to play football, 20 of them like to play basketball, and 10 of them don’t like these two sports, so how many people like both sports in total? people.
小华调查了运动队的40位同学，爱好踢球的有25人，爱好打篮球的有20人，其中这两种运动都不爱的有10人，那么两种运动都爱好的一共有多少人．
<gadget id="calculator">40 - 10</gadget>
<output>30</output>

<gadget id="calculator">20 - 30</gadget>
<output>-10</output>

<gadget id="calculator">25 + (-10)</gadget>
<output>15</output>

<result>15</result>