Question

Автомобиль находился в пути 3 ч. в первый час он проехал 54 км., во второй - в 1,5 раза больше, чем в первый. Путь, пройденный в третий час, составляет 0,8 пути, пройденного во второй час. Найдите среднюю скорость автомобиля. помогите пожалуйста

Answer 1

Скорость во второй час = 54*1,5=81 км/час
Скорость в третий час = 81*0,8= 64,8 км/ час
Средняя скорость (54+81+64,8) : 3= 66,6 км/час

Answer 2

Problem Analysis

We are given that a car was traveling for 3 hours. In the first hour, it traveled 54 km. In the second hour, it traveled 1.5 times more than in the first hour. In the third hour, the distance traveled is 0.8 times the distance traveled in the second hour. We need to find the average speed of the car.

Solution

Let's break down the problem step by step.

1. Calculate the distance traveled in the second hour. - We are given that the car traveled 1.5 times more in the second hour than in the first hour. - So, the distance traveled in the second hour is 1.5 times 54 km. - Therefore, the distance traveled in the second hour is 81 km.

2. Calculate the distance traveled in the third hour. - We are given that the distance traveled in the third hour is 0.8 times the distance traveled in the second hour. - So, the distance traveled in the third hour is 0.8 times 81 km. - Therefore, the distance traveled in the third hour is 64.8 km.

3. Calculate the total distance traveled. - The total distance traveled is the sum of the distances traveled in each hour. - So, the total distance traveled is 54 km + 81 km + 64.8 km. - Therefore, the total distance traveled is 199.8 km.

4. Calculate the average speed. - Average speed is defined as the total distance traveled divided by the total time taken. - We are given that the car traveled for 3 hours. - So, the average speed is 199.8 km divided by 3 hours. - Therefore, the average speed of the car is 66.6 km/h.

Answer

The average speed of the car is 66.6 km/h.