Problems during the trip: Our family took advantage of the May Day holiday to travel to other places by car. There was a section of the road that required a speed limit. The car was traveling at a con

Problems during the trip: Our family took advantage of the May Day holiday to travel to other places by car. There was a section of the road that required a speed limit. The car was traveling at a constant speed on the highway.

The three-digit number is the original two-digit number plus zero in the middle, then the highest digit should be 1. Suppose the other number is Equation:

The size of the number you see for the first time is 1x, the second time is 10x+1, and the third time is 10x,

(10x) -(10x+1)=(10x+1)-(1x)

The solution is x=6

The three-dimensional mileage mark is, 16, 61, 106, then because of the middle interval for an hour, so the speed is 61-16=45 kilometers per hour.