Question

Велосипед эист проехал от деревни до города со скоростью 12км ч обратно он ехал со скоростью 18км ч приехал на 15 минут раньше . Сколько км от города до деревни?

Answer 1

Calculation of Distance

To calculate the distance between the village and the city, we can use the formula:

Distance = Speed x Time

Let's denote the distance from the village to the city as 'd' kilometers.

When the cyclist traveled from the village to the city at a speed of 12 km/h, the time taken can be calculated as:

Time1 = Distance / Speed1

Similarly, when the cyclist traveled from the city back to the village at a speed of 18 km/h, the time taken can be calculated as:

Time2 = Distance / Speed2

According to the given information, the cyclist arrived at the destination 15 minutes earlier than expected. This means that the time taken for the return journey was 15 minutes less than the time taken for the initial journey.

So, we can write the equation:

Time2 = Time1 - 15 minutes

Now, let's substitute the values into the equations and solve for the distance.

Solution

Using the formula for time:

Time1 = d / 12

Time2 = d / 18

According to the given information, the time for the return journey is 15 minutes less than the time for the initial journey:

Time2 = Time1 - 15 minutes

Substituting the values:

d / 18 = d / 12 - 15 minutes

To simplify the equation, let's convert 15 minutes to hours:

15 minutes = 15 / 60 = 0.25 hours

Now, let's solve the equation:

d / 18 = d / 12 - 0.25

Multiplying both sides of the equation by 36 (the least common multiple of 18 and 12) to eliminate the denominators:

2d = 3d - 9

Simplifying the equation:

d = 9

Therefore, the distance between the village and the city is 9 kilometers.

Answer

The distance from the city to the village is 9 kilometers.