A ship from a downstream 9 hours to B, the original way back 11 hours to reach a, known water velocity is 2 km / h, find the ship's speed in still water The distance between a and B

A ship from a downstream 9 hours to B, the original way back 11 hours to reach a, known water velocity is 2 km / h, find the ship's speed in still water The distance between a and B

Let v be the speed of a ship, then V + 2 is the speed downstream and V-2 is the speed upstream
Because the distance between the two places is equal, then
(V+2)*9=(V-2)*11
9V+18=11V-22
2V=40
V=20km/h
The distance between a and B is (20 + 2) * 9 = 198km

It takes 9h for the ship to go downwind from place a to place B, and 11h for the ship to return from the original road. The water velocity is 2km / h, and the static water velocity and the distance between place a and place B are calculated

Let the static water velocity of the ship be x km / h
9（x+2）=11（x-2）
9x+18=11x-22
2x=40
x=20
9 × (20 + 2) = 198km
A: the still water speed of the ship is 20 kilometers per hour
The distance between a and B is 198km

It takes 3 hours for a ship to go downstream from land a to land B, and 9 hours for a ship to go upstream from land B to land a. the speed of the current is 2 km / h
Distance

Let the speed of a be x km / h
[equivalent relation: the distance from a to B = the distance from B to a]
3（2+x）=9（x-2）
The solution is: x = 4
3×（4+2）=18（ km）
The distance between a and B is 18 km

The speed of the car is 28km / h on the uphill and 42km / h on the downhill. It takes 4 and 1 / 2 h to go from land a to land B, and it takes 4 hours and 40 minutes to go back
How many kilometers are the uphill and downhill from land a to land B?

It takes 1 / 28-1 / 42 hours less to travel 1 km uphill than 1 km downhill,
It takes 10 minutes less to go from a to B than from B to a = 1 / 6 hour,
From land a to land B, the uphill slope is 1 / 6 (1 / 28-1 / 42) = 14km less than the downhill slope;
It takes 1 / 28 + 1 / 42 hours to travel 1 km uphill and 1 km downhill,
It takes 4.5-14 ÷ 42 = 25 / 6 hours to get from land a to land B, except that the downhill is more than the uphill by 14 km,
From a to B, the uphill slope is (25 / 6) / (1 / 28 + 1 / 42) = 70 km, and the downhill slope is 70 + 14 = 84 km

It took three hours for a car to drive from a to B with an average speed of 105km, and then it took two hours to reach B in the mountains with a speed of 28km per hour
Find the average speed of the car from ground a to ground B

Average speed = (105 + 28 × 2) / (3 + 2) = 32.2km/h

It is planned to take 5.5 hours for a car to go from place a to place B. due to the difficulty of 28 km of Road on the way, the speed is only 75% of the original speed. Therefore, the time to arrive at place B is shorter than that of the original time
The original plan is 12 minutes late. How many kilometers is the distance between a and B,

If it is difficult to walk at the original speed, it will take time: 12 / 60 (1 / 75% - 1) = 0.6 hours
Original speed: 28 △ 0.6 = 140 / 3km / h
Distance between a and B: 140 / 3 × 5.5 = 770 / 3km

The speed of the car is 28km / 1 uphill and 42km / h downhill. It takes 4.2% of the time to go from land a to land B and 4.3% of the time to return
How many times are the uphill and downhill from land a to land B? Thank you for your help! You'll have to wait for it. You need a quadratic equation of two variables! Remember

From a to B, the uphill is x km and the downhill is y km
X÷28 Y÷42=4.5
Y÷28 X÷42=14/3
The solution is x = 70, y = 84
So the uphill time is 70 △ 28 = 2.5
Downhill time 4.5-2.5 = 2

The speed of the car was 28km / h uphill and 42km / h downhill. It took 4.25 hours to get from land a to land B and 4.40 minutes to return,
How many kilometers are the uphill and downhill from land a to land B
Note that the return time is 4.25 hours and the solution of the equation is given

The uphill is x km and the downhill is y km
x/28+y/42=4.25
x/42+y/28=4
3x+2y=357
2x+3y=336
x=79.8
y=58.8

One car drove 160km from place a to place B, which is exactly 4 / 7 of the whole journey; the other car drove 1 / 4 of the whole journey from place B to place A. how many kilometers are there between a and B? How many kilometers did the second car drive?
Equation!

The distance between a and B is x km
4/7x=160
x=280
280×¼=70
The distance between a and B is 280 km, and the second car has driven 70 km

One car drove 160km from a to B, which is exactly 4 / 7 of the whole journey. Another car drove 1 / 7 of the whole journey from B to a
One car drove 160km from place a to place B, which is exactly 4 / 7 of the whole journey. The other car drove 1 / 4 of the whole journey from place B to place A. how far is the distance between Party A and Party B? How far is the second car?
equation

If a and B meet as X, then 4 / 7X = 160, x = 280; if the second car runs 1 / 4 of the whole journey, then 70;
So Party A and Party B get together for 280km, and the second car runs 70km