Question

Два пешехода вышли одновременно из двух деревень навстречу друг другу и встретились через 20 минут. За сколько минут второй пешеход проходит расстояние между этими пунктами, если первый пешеход проходит это расстояние за 36 минут?

Answer 1

ДАНО
Tвстр = 20 мин -  время встречи
Т1 = 36 мин - время первого
НАЙТИ
Т2 =? -  время второго
РЕШЕНИЕ
Скорость первого
V1 = S/36
Расстояние через время встречи
S = (V2+ S/36)*20  = 20*V2 + 5/9*S
Отсюда 
V2 = (1 -5/9)/20 = 1/45*S
И ВРЕМЯ второго
Т2 = S/V2 = 45 минут - ОТВЕТ

Answer 2

Problem Analysis

We have two pedestrians who start walking towards each other from two different villages. They meet after 20 minutes. We need to determine how long it takes for the second pedestrian to cover the distance between the two villages, given that the first pedestrian covers the distance in 36 minutes.

Solution

Let's assume the distance between the two villages is D.

We know that the first pedestrian covers the distance in 36 minutes, so their speed can be calculated as D/36.

Since the two pedestrians are walking towards each other, their combined speed is the sum of their individual speeds.

Let's denote the speed of the second pedestrian as S2.

The combined speed of the two pedestrians is D/36 + S2.

We also know that they meet after 20 minutes. The distance covered by the first pedestrian in 20 minutes is (D/36) * 20.

The remaining distance for the second pedestrian to cover is D - (D/36) * 20.

We can set up the equation:

(D - (D/36) * 20) / S2 = 20

Simplifying the equation, we get:

D - (D/36) * 20 = 20 * S2

Solving for S2, we get:

S2 = D / (20 - (D/36))

Now we can substitute the given value of D and calculate S2.

Calculation

Let's calculate the value of S2 using the given information.

Given: - The first pedestrian covers the distance in 36 minutes. - They meet after 20 minutes.

Using the equation S2 = D / (20 - (D/36)), we can substitute the value of D as 36 and calculate S2.

S2 = 36 / (20 - (36/36))

Simplifying the equation, we get:

S2 = 36 / (20 - 1)

S2 = 36 / 19

S2 ≈ 1.895

Therefore, the second pedestrian takes approximately 1.895 minutes to cover the distance between the two villages.

Answer

The second pedestrian takes approximately 1.895 minutes to cover the distance between the two villages, given that the first pedestrian covers the distance in 36 minutes.