There are 40 students in a class, 25 of them like basketball, 20 of them like table tennis, and 8 of them don’t like both. How many people like both basketball and table tennis?
某班共40人，其中25人喜爱篮球运动，20人喜爱乒乓球运动，8人对这两项都不喜爱，则既喜爱篮球运动又喜爱乒乓球运动的人数为多少人．
<gadget id="calculator">40 - 8</gadget>
<output>32</output>

<gadget id="calculator">20 - 32</gadget>
<output>-12</output>

<gadget id="calculator">25 + (-12)</gadget>
<output>13</output>

<result>13</result>