There are 21 people in the art group of the school, 3 people in the paper-cutting group are less than the art group, the number of basketball group is 4 times that of the paper-cutting group, how many people are there in the basketball group?
学校美术兴趣小组有21人，刻纸兴趣小组比美术组少3人，篮球兴趣小组的人数是刻纸兴趣小组的4倍，篮球兴趣小组有多少人？
<gadget id="calculator">21 - 3</gadget>
<output>18</output>

<gadget id="calculator">18 * 4</gadget>
<output>72</output>

<result>72</result>