factory sends a car to pick up the chief engineer on time every morning. To ensure safety, when returning to the factory, the speed of the car is 80% of the speed when it came, and the car is set to move at a constant speed to and fro, and the U-turn time is not counted. One day, in order to arrive at the factory earlier, the chief engineer set off 1 hour earlier than usual and walked to the factory. After walking for a while, she met the car that came to pick her up and continued on. After arriving at the factory, he found that he only arrived 18 minutes earlier than usual. How many minutes did the chief engineer walk on the road before meeting the car that came to pick him up.
某工厂每天早晨都派小汽车按时接总工程师上班，为保证安全，返回工厂时，小汽车车速为来时的80%，设汽车往返均做匀速运动，掉头时间不计．有一天，总工程师为了早些到厂，比平时提前1h出发步行去厂，走了一段时间后，遇到来接她的小汽车再上车继续前进．到厂后他发现只比平时早到18min．则总工程师在路上步行了多少min才遇上来接他的小汽车．
<gadget id="calculator">1 + 1.25</gadget>
<output>2.25</output>

<gadget id="calculator">18 / 2.25</gadget>
<output>8</output>

<gadget id="calculator">60 - 8</gadget>
<output>52</output>

<result>52</result>