At one event, a car was arranged to pick up Secretary Zhang. It was planned to leave at 7 o’clock and take 80 minutes to and fro. As a result, Secretary Zhang started to come here at 7 o’clock, so the car returned to the venue 10 minutes earlier. How many times faster than Secretary Zhang?
有一次活动，安排了一辆车去接张书记，计划7点出发，往返80分钟，结果张书记在7点就开始往这边走来，于是这辆车提前了10分钟回到会场，则车速是张书记的多少倍？
<gadget id="calculator">80 / 2</gadget>
<output>40</output>

<gadget id="calculator">10 / 2</gadget>
<output>5</output>

<gadget id="calculator">40 - 5</gadget>
<output>35</output>

<gadget id="calculator">35 / 5</gadget>
<output>7</output>

<result>7</result>