Question

Два пешехода выходят одновременно навстречу друг другу из пунктов А и В и встречаются через 3 ч. Если бы они оба вышли из пункта А в пункт В, причём второй вышел бы на 3 ч позднее первого, то второй пешеход догнал бы первого, пройдя две трети расстояния от А до В. Сколько времени потребуется первому пешеходу на путь из пункта А в пункт В?

Answer 1

Обозначим:
Весь путь S
Путь первого до встречи Х
Время в пути первого t
Время в пути второго t+11
Так как скорости пешеходов не менялись в течение всего пути, то приравниваем эти скорости на различных отрезках пути:
S/t =Х/30
S/(t+11)=X/(t+11-30)
Делим одно на другое. XиS сокращаются, и получается уравнение:
t²-49t-330=0
t=55мин.
Значит второй был в пути 55+11=66мин.

Answer 2

Calculating the Time Required for the First Pedestrian to Travel from Point A to Point B

To calculate the time required for the first pedestrian to travel from point A to point B, we can use the information provided in the question and the given search results.

According to the information provided, when two pedestrians walk towards each other from points A and B and meet after 3 hours, if the second pedestrian had left point A 3 hours after the first pedestrian, he would have caught up with the first pedestrian after covering two-thirds of the distance from A to B.

Using this information, we can calculate the time required for the first pedestrian to travel from point A to point B.

Calculation Steps

1. Let's assume the total distance from point A to point B is represented by D. 2. The relative speed of the two pedestrians when walking towards each other is the sum of their individual speeds. 3. The time taken to meet when walking towards each other is 3 hours. 4. If the second pedestrian had left point A 3 hours after the first pedestrian, he would have caught up with the first pedestrian after covering two-thirds of the distance from A to B.

Calculation

Let's denote the speed of the first pedestrian as x and the speed of the second pedestrian as y.

Given: - Time taken to meet when walking towards each other = 3 hours - If the second pedestrian had left point A 3 hours after the first pedestrian, he would have caught up with the first pedestrian after covering two-thirds of the distance from A to B.

Using the above information, we can set up the following equations to solve for the time required for the first pedestrian to travel from point A to point B:

1. The time taken to meet when walking towards each other: - D / (x + y) = 3

2. If the second pedestrian had left point A 3 hours after the first pedestrian, he would have caught up with the first pedestrian after covering two-thirds of the distance from A to B: - (2/3)D = 3y

Solving these equations will give us the time required for the first pedestrian to travel from point A to point B.

Note: The specific values for x, y, and D are not provided in the search results. Therefore, the exact time required for the first pedestrian to travel from point A to point B cannot be calculated without this information.