A total of 39 people participated in the rope skipping activity, of which the number of boys was twice that of girls, and boys accounted for ((())/(())) of the total number.
参加跳绳活动的共有39人，其中男生人数是女生人数的2倍，男生占总人数的((())/(()))．
<gadget id="calculator">2 + 1</gadget>
<output>3</output>

<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<result>2/3 = around 0.666667</result>