The policeman stopped the car driver for regular control, the speed limit on the highway section was 120km / h, he legitimized the driver and asked him a few routine questions:
POLICEMAN: How long were you driving today?
DRIVER: I left Zagreb at 5.45 a.m. this morning.
POLICEMAN: Now it’s exactly 10 a.m. From Zagreb you have crossed 510 km. It’s very tedious.
DRIVER: No, not at all, because I like fast driving. After two hours of driving I made 20 minutes break, besides that I was stuck in traffic jam for another 20 minutes, and the rest of the ride went well.
POLICEMAN: (He paused and seemed to think), when he reached the conclusion, he told the driver: ‘I think your driving this time will cost you a lot’.
The task: Understand the words of the Policeman!
Explanation: The time the driver came from Zagreb to the stop where the stop was:
10h – 5h and 45 min = 4h and 15min. What turned into hours is 4.25 h.
From that time on, he stood for 40 minutes (resting), which, when he had spoken in the hours:
40 min = (40: 60) h = 0.66 h.
From the data it can be seen that the driver was actively driving:
4.25 h – 0, 66 h = 3.6 h;
The length of the road that has so far switched is 510 km, the average speed with which the driver is driving can be calculated from the ratio:
Conclusion: The speed which is allowed to travel is 120km / h, so it is clear that the driver has exceeded the permitted speed. It is clear that the Policeman wanted to punish a driver for failure to comply with traffic regulations. Only what is not clear is that the Policeman so quickly came to the conclusion that the driver made a violation?