Question

Из пункта А в пункт, В расстояние между которыми 17 км, вышел пешеход со скоростью 4 км/ч . Через 15 мин из В в А навстречю ему выехал велосепидист со скоростью 12 км/ч . Какое расстояние до встречи преодолел велосипедист , а какое - пешеход?

Answer 1

Пешеход шел до встречи х часов,тогда велосипедист ехал до встречи (х - 0,25) часа.

зарисовки для уравнения:

Пешеход прошел до встречи-(4*х) км.

Велосипедист-12*(х-0,25)км.
Составим уравнение:

4х + 12(х-0,25)=17 
4х +12х-3=17 
16х=20 
х=1,25 часа.

пешеход шел до встречи со скоростью 4 км/час 
Значит он прошел 4*1,25=5 км,значит велосипедист проехал со скоростью 12 км/ч. 

 

 

Answer 2

Problem Analysis

We are given two points, A and B, with a distance of 17 km between them. A pedestrian starts walking from point A towards point B at a speed of 4 km/h. After 15 minutes, a cyclist starts cycling from point B towards point A at a speed of 12 km/h. We need to find the distance traveled by the cyclist and the pedestrian until they meet.

Solution

To solve this problem, we can use the formula: distance = speed × time.

Let's calculate the distance traveled by the pedestrian and the cyclist.

Distance Traveled by the Pedestrian

The pedestrian walks at a speed of 4 km/h. We need to convert the time of 15 minutes to hours by dividing it by 60.

Time taken by the pedestrian = 15 minutes ÷ 60 = 0.25 hours

Now, we can calculate the distance traveled by the pedestrian using the formula:

Distance = Speed × Time

Distance = 4 km/h × 0.25 hours

Distance = 1 km

Therefore, the pedestrian has traveled a distance of 1 km.

Distance Traveled by the Cyclist

The cyclist cycles at a speed of 12 km/h. We need to find the time taken by the cyclist to meet the pedestrian.

The time taken by the cyclist can be calculated by subtracting the time taken by the pedestrian from the total time of 15 minutes.

Time taken by the cyclist = Total time - Time taken by the pedestrian

Time taken by the cyclist = 15 minutes - 15 minutes

Time taken by the cyclist = 0 minutes

Since the cyclist starts from point B and meets the pedestrian after 0 minutes, it means they meet immediately. Therefore, the distance traveled by the cyclist is 0 km.

Therefore, the cyclist has traveled a distance of 0 km.

Summary

In summary, the distance traveled by the cyclist is 0 km and the distance traveled by the pedestrian is 1 km.

Please let me know if I can help you with anything else.