There are 42 students in the science and technology interest group. Among them (4/7) are boys, how many boys are there?
科技兴趣小组有42名学生．其中(4/7)是男生，男生有多少人．
<gadget id="calculator">4 / 7</gadget>
<output>4/7 = around 0.571429</output>

<gadget id="calculator">42 * (4/7)</gadget>
<output>24</output>

<result>24</result>