75 students participated in the rope skipping activity, and every 5 people prepared a skipping rope. There are now 8 skipping ropes, how many skipping ropes should be prepared?
75个同学参加跳绳活动，每5个人准备一根跳绳，现已有8根跳绳，还要准备多少根跳绳？
<gadget id="calculator">75 / 5</gadget>
<output>15</output>

<gadget id="calculator">15 - 8</gadget>
<output>7</output>

<result>7</result>