If the speed of a car from a to B is increased to 25%, it can arrive 25 minutes earlier than the original time. If the speed is increased to 1 / 3 after driving 80 km, it can arrive at B 10 minutes earlier to find the distance between a and B

If the speed of a car from a to B is increased to 25%, it can arrive 25 minutes earlier than the original time. If the speed is increased to 1 / 3 after driving 80 km, it can arrive at B 10 minutes earlier to find the distance between a and B

Let: the distance between a and b s, the original speed V, the normal time t = s / V;
According to the meaning: ① s / (V + 25% v) = (s / V) - 25;
②(80/v)+(S-80)/(v+1/3v)=(S/v)-10;
100S=125S-25*125v;
320+3S-240=4S-40v;
s=125v;
S-40v=80;
S = 2000 / 17 km

If the speed of a car increases by 20%, it can arrive one hour earlier. If the speed of the first 100 kilometers increases by 30%, it can arrive one hour earlier
A car can arrive one hour ahead of time from place a to place B. if the speed of the first 100 kilometers is the same as the original speed, and then the speed is increased by 30%, it can arrive one hour ahead of time. How many kilometers are there between the two places?
, as long as the expression

The length of the two places is s km and the speed is v km / h
s/v=s/1.2v+1
s/v=100/v+(s-100)/1.3v+1
So s / 1.2V + 1 = 100 / V + (S-100) / 1.3V + 1
s/1.2=100+(s-100)/1.3
1.3s=156+1.2s-120
0.1s=36
s=360
So AB is 360 kilometers long

How to use cement and coagulant?

General cement should have a certain period of setting and maintenance, otherwise the quality is not guaranteed, but in order to catch up with the progress of the project and ensure the quality of the project, it is necessary to add accelerator (coagulant)