The number of students in Class 1 is between 40 and 50, among whom (2/3) like to skip rope, and (2/7) like to jump with rubber bands. How many students are there in Class 1?
六1班学生的人数在40～50人之间，其中(2/3)喜欢跳绳，(2/7)喜欢跳橡皮筋，请问六1班有多少人．
<gadget id="calculator">3 * 7</gadget>
<output>21</output>

<gadget id="calculator">21 * 2</gadget>
<output>42</output>

<result>42</result>