Question

Из A и B со скоростью 3,6 км/ч вышел пешеход. Через 1ч 15 мин навстречу ему из В со скоростью 4,8 км/ч вышел другой пешеход. В А и В пешеходы прибыли одновременно. Найдите расстояние между А и В.

Answer 1

V1=3,6 км/ч
V2=4,8 км/ч
t1=t2+1 1/4 ч
Пусть х - время, за которое второй пешеход прошёл расстояние. Тогда время первого пешехода будет х+1¼. Они прошли одно и то же расстояние. Составим уравнение:
3,6(х+1¼)=4,8х
3,6х+4,5=4,8х
1,2х=4,5
х=3,75= 3 ¾
Второй пешеход прошёл расстояние за 3 ¾ часа, значит расстояние будет 3,75×4,8=18 км.
Проверка. Первый пешеход прошёл за 3 ¾+1 ¼= 5 часов. Тогда расстояние равно 3,6×5=18 км.
Ответ: 18 км

Answer 2

Problem Analysis

We are given that two pedestrians, one starting from point A and the other from point B, are walking towards each other. The pedestrian from point A is walking at a speed of 3.6 km/h, while the pedestrian from point B is walking at a speed of 4.8 km/h. After 1 hour and 15 minutes, they meet each other, and we need to find the distance between points A and B.

Solution

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

Distance = Speed × Time

Let's calculate the distances traveled by each pedestrian and then find the total distance between points A and B.

1. Convert the time of 1 hour and 15 minutes to hours: - 1 hour = 60 minutes - 15 minutes = 15/60 = 0.25 hours

2. Calculate the distance traveled by the pedestrian from point A: - Speed = 3.6 km/h - Time = 1.25 hours - Distance_A = Speed × Time

3. Calculate the distance traveled by the pedestrian from point B: - Speed = 4.8 km/h - Time = 1.25 hours - Distance_B = Speed × Time

4. Calculate the total distance between points A and B: - Total Distance = Distance_A + Distance_B

Let's calculate the distances using the given information.

Calculation

1. Convert the time of 1 hour and 15 minutes to hours: - 1 hour + 0.25 hours = 1.25 hours

2. Calculate the distance traveled by the pedestrian from point A: - Speed = 3.6 km/h - Time = 1.25 hours - Distance_A = 3.6 km/h × 1.25 hours

3. Calculate the distance traveled by the pedestrian from point B: - Speed = 4.8 km/h - Time = 1.25 hours - Distance_B = 4.8 km/h × 1.25 hours

4. Calculate the total distance between points A and B: - Total Distance = Distance_A + Distance_B

Let's perform the calculations.

Calculation Results

1. Convert the time of 1 hour and 15 minutes to hours: - 1 hour + 0.25 hours = 1.25 hours

2. Calculate the distance traveled by the pedestrian from point A: - Speed = 3.6 km/h - Time = 1.25 hours - Distance_A = 3.6 km/h × 1.25 hours = 4.5 km

3. Calculate the distance traveled by the pedestrian from point B: - Speed = 4.8 km/h - Time = 1.25 hours - Distance_B = 4.8 km/h × 1.25 hours = 6 km

4. Calculate the total distance between points A and B: - Total Distance = Distance_A + Distance_B = 4.5 km + 6 km = 10.5 km

Therefore, the distance between points A and B is 10.5 km.

Answer

The distance between points A and B is 10.5 km.