Question

Велосипедист проехал путь АВ со скоростью 12 км.ч. Возвращаясь из А в В, он развил скорость 18 км.ч. и затратил на обратный путь на 15 мин меньше, чем на путь из А в В. Сколько километров между А и В?

Answer 1

Пусть х будет расстояние.

15мин = 0,25

x/12-x/18=1/4

6х-4х=18

2х=18

х=9

 

Answer 2

Calculation of Distance between A and B

To calculate the distance between points A and B, we can use the formula:

Distance = Speed x Time

Let's denote the distance from A to B as AB and the distance from B to A as BA.

Given the information provided, we know the following:

- The cyclist traveled from A to B with a speed of 12 km/h. - The cyclist returned from B to A with a speed of 18 km/h. - The time taken for the return journey (BA) was 15 minutes less than the time taken for the journey from A to B (AB).

Let's calculate the distance between A and B using the given information.

1. Calculate the time taken for the journey from A to B (AB): - Let's assume the time taken for AB is t hours. - Using the formula Distance = Speed x Time, we have: AB = 12 km/h x t hours

2. Calculate the time taken for the return journey from B to A (BA): - The time taken for BA is 15 minutes less than the time taken for AB. - Since 15 minutes is equal to 0.25 hours, the time taken for BA is t - 0.25 hours.

3. Calculate the distance between A and B: - The distance from A to B (AB) is the same as the distance from B to A (BA). - Therefore, AB = BA. - Using the formula Distance = Speed x Time, we have: AB = 18 km/h x (t - 0.25) hours

Since AB = BA, we can equate the two expressions for AB:

12t = 18(t - 0.25)

Solving this equation will give us the value of t, which we can then use to calculate the distance between A and B.

Let's solve the equation:

12t = 18(t - 0.25)

12t = 18t - 4.5

6t = 4.5

t = 4.5 / 6

t = 0.75 hours

Now that we have the value of t, we can calculate the distance between A and B:

AB = 12 km/h x 0.75 hours

AB = 9 km

Therefore, the distance between points A and B is 9 kilometers.

Answer

The distance between points A and B is 9 kilometers.