15 students went to origami cranes, and each person had to fold 7 cranes on average. At this time, a few more people came, and everyone creatively assigned tasks, and each person folded 5 cranes on average. How many people have come?
15名学生去折纸鹤，平均每人要折7只，这时又来了几人，大家创新分配任务，平均每人折5只．有来了几人？
<gadget id="calculator">7 / 5</gadget>
<output>7/5 = around 1.4</output>

<gadget id="calculator">15 * (7/5)</gadget>
<output>21</output>

<gadget id="calculator">21 - 15</gadget>
<output>6</output>

<result>6</result>