Question

Грузовая машина проезжает между двумя городами за 30 часов Если грузовая и легковая машина одновременно отправиться за тетрадок навстречу друг другу плане встретиться Через 12 часов За сколько часов расстояние между городами приезжает легковая машина

Answer 1

Ск груз= 1/30 пути час

ск сбл - 1/12 пути час

ск легк машины 1/12-1/30=5/60-2/60=3/60=1/20 пути час

следовательно машина пройдет за 20 часов

Answer 2

Problem Analysis

We have a situation where a truck and a car are traveling towards each other from two different cities. The truck takes 30 hours to travel between the cities. We need to determine how long it will take for the car to reach the distance between the cities after they start traveling towards each other.

Solution

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

We know that the truck takes 30 hours to travel the distance D. Therefore, the truck's speed can be calculated as D/30.

Now, let's consider the time it takes for the car to reach the distance between the cities after they start traveling towards each other. We are given that they start traveling towards each other at the same time and after 12 hours, they meet.

During these 12 hours, the truck has traveled for 12 hours at its speed, which is D/30. Therefore, the distance traveled by the truck in 12 hours is 12 * (D/30) = 2D/5.

Since the car and the truck are traveling towards each other, the combined distance they cover in 12 hours is equal to the distance between the cities, which is D.

Therefore, we can write the equation: 2D/5 + x = D, where x is the distance traveled by the car in the given time.

Simplifying the equation, we get: x = 3D/5.

Since the car's speed is constant, we can calculate the time it takes for the car to travel the distance 3D/5 using the car's speed, which is D/t, where t is the time taken by the car.

Simplifying the equation, we get: t = 5/3.

Therefore, it will take the car 5/3 hours to reach the distance between the cities after they start traveling towards each other.

Answer

The car will reach the distance between the cities in 5/3 hours.

Explanation

When the truck and the car start traveling towards each other, they meet after 12 hours. During these 12 hours, the truck has traveled a distance of 2D/5, and the car has traveled a distance of 3D/5. Since the car's speed is constant, it will take the car 5/3 hours to reach the distance between the cities after they start traveling towards each other.