There are 70 students in a class, and they are divided into three groups to participate in mathematics interest group activities. The ratio of the number of people in the first group to the second group is 2:3, and the ratio of the number of people in the second group to the third group is 4:5. How many people are in the group.
某班人数为70人，先分成三组参加数学兴趣小组活动，第一组与第二组的人数比为2比3，第二组与第三组的人数比为4比5，则第一组的人数为多少人．
<gadget id="calculator">8 + 12 + 15</gadget>
<output>35</output>

<gadget id="calculator">8 / 35</gadget>
<output>8/35 = around 0.228571</output>

<gadget id="calculator">70 * (8/35)</gadget>
<output>16</output>

<result>16</result>