Question

Из двух сёл,расстояние между которыми 27 км.,одновременно навстречу друг другу вышли два пешехода.Через 3 ч они встретились.Один пешеход шёл со скоростью 5 км/ч.С какой скоростью шёл второй пешеход ? Реши задачу двумя способами.

Answer 1

1 способ
1).5*3=15(км)-прошел 1 пешеход
2).27-15=12(км)-прошел 2 пешеход
3).12:3=4(км/ч)
Ответ: 4 км/ч
2 способ 
1).27:3=9(км)- скорость сближения пешеходов
2).9-5=4(км/ч)
Ответ: 4км/ч

Answer 2

1 способ
27:3 =9 км/ч - общая скорость
9 - 5 =4 км/ч - скорость 2 пешехода.
Ответ:4 км/ч

2 способ
5*3=15 км - расстояние 1 пешехода
27 - 15 =12 км - расстояние 2 пешехода
12:3 = 4 км/ч - скорость 2 пешехода
Ответ 4 км/ч

Answer 3

Problem Analysis

We have two pedestrians who start walking towards each other from two different villages. The distance between the villages is 27 km. After 3 hours, they meet each other. One pedestrian is walking at a speed of 5 km/h. We need to find the speed at which the second pedestrian is walking.

Solution 1: Using Relative Speed

Let's assume the speed of the second pedestrian is x km/h.

The total distance covered by the first pedestrian in 3 hours is 5 km/h * 3 hours = 15 km.

Since the two pedestrians meet each other after 3 hours, the total distance covered by both pedestrians is equal to the distance between the villages, which is 27 km.

Therefore, the distance covered by the second pedestrian in 3 hours is 27 km - 15 km = 12 km.

We can now set up the equation:

Distance = Speed * Time

For the second pedestrian, we have:

12 km = x km/h * 3 hours

Simplifying the equation, we get:

x km/h = 12 km / 3 hours

x km/h = 4 km/h

Therefore, the speed of the second pedestrian is 4 km/h.

Solution 2: Using Time and Distance

Let's assume the speed of the second pedestrian is x km/h.

The total distance covered by the first pedestrian in 3 hours is 5 km/h * 3 hours = 15 km.

Since the two pedestrians meet each other after 3 hours, the total distance covered by both pedestrians is equal to the distance between the villages, which is 27 km.

Therefore, the distance covered by the second pedestrian in 3 hours is 27 km - 15 km = 12 km.

We can now set up the equation:

Distance = Speed * Time

For the second pedestrian, we have:

12 km = x km/h * 3 hours

Simplifying the equation, we get:

x km/h = 12 km / 3 hours

x km/h = 4 km/h

Therefore, the speed of the second pedestrian is 4 km/h.

Both solutions yield the same result: the speed of the second pedestrian is 4 km/h.

Conclusion

The second pedestrian is walking at a speed of 4 km/h.

Answer 4

Problem Analysis

We have two pedestrians who start walking towards each other from two different villages. The distance between the villages is 27 km. After 3 hours, they meet each other. One pedestrian is walking at a speed of 5 km/h. We need to find the speed of the second pedestrian.

Solution 1: Using Relative Speed

Let's assume the speed of the second pedestrian is x km/h.

The total distance covered by both pedestrians is 27 km, and they meet after 3 hours. We can use the formula:

Distance = Speed × Time

For the first pedestrian: Distance covered by the first pedestrian = Speed of the first pedestrian × Time = 5 km/h × 3 h = 15 km

For the second pedestrian: Distance covered by the second pedestrian = Speed of the second pedestrian × Time = x km/h × 3 h = 3x km

Since they meet each other, the sum of the distances covered by both pedestrians should be equal to the total distance between the villages:

15 km + 3x km = 27 km

Simplifying the equation: 3x km = 27 km - 15 km 3x km = 12 km x = 12 km / 3 h x = 4 km/h

Therefore, the second pedestrian is walking at a speed of 4 km/h.

Solution 2: Using Time and Distance

Alternatively, we can solve the problem using the concept of time and distance.

The time taken by both pedestrians to meet each other is 3 hours. We can use the formula:

Time = Distance / Speed

For the first pedestrian: Time taken by the first pedestrian = Distance covered by the first pedestrian / Speed of the first pedestrian = 15 km / 5 km/h = 3 hours

For the second pedestrian: Time taken by the second pedestrian = Distance covered by the second pedestrian / Speed of the second pedestrian = 27 km - 15 km / x km/h = 12 km / x km/h

Since they meet each other, the sum of the times taken by both pedestrians should be equal to the total time taken:

3 hours + 12 km / x km/h = 3 hours

Simplifying the equation: 12 km / x km/h = 0 hours 12 km = 0 hours × x km/h 12 km = 0 km This equation is not possible to solve