Question

Реши задачи. Электричка за три часа проехала 145 км. Сколько километров она проезжала за каждый из этих часов, если за первые два часа она проехала 98 км, а за третий час на 3 км меньше, чем за второй? Помогите пожалуйста!

Answer 1

За трети час 145- 98=47км
за второй час 47+3=50км
за первый 98-50=48км

Answer 2

Problem Analysis

We are given that a train traveled 145 km in three hours. We need to find out how many kilometers it traveled in each of the three hours, given that it traveled 98 km in the first two hours and 3 km less in the third hour compared to the second hour.

Solution

Let's solve this problem step by step.

1. We know that the train traveled a total of 145 km in three hours. Therefore, the average speed of the train can be calculated by dividing the total distance traveled by the total time taken: - Average speed = Total distance / Total time - Average speed = 145 km / 3 hours - Average speed = 48.33 km/h.

2. We are given that the train traveled 98 km in the first two hours. To find the speed of the train during this period, we can divide the distance traveled by the time taken: - Speed for the first two hours = Distance / Time - Speed for the first two hours = 98 km / 2 hours - Speed for the first two hours = 49 km/h.

3. We are also given that the train traveled 3 km less in the third hour compared to the second hour. Let's assume that the distance traveled in the second hour is x km. Therefore, the distance traveled in the third hour would be (x - 3) km.

4. We can use the average speed of the train to find the time taken for the third hour: - Average speed = Distance / Time - Average speed = (x + (x - 3)) km / 3 hours - 48.33 km/h = (2x - 3) km / 3 hours - 2x - 3 = 48.33 * 3 - 2x - 3 = 144.99 - 2x = 144.99 + 3 - 2x = 147.99 - x = 147.99 / 2 - x ≈ 74 km.

5. Therefore, the train traveled 74 km in the second hour and (74 - 3) km = 71 km in the third hour.

Answer

The train traveled 98 km in the first hour, 74 km in the second hour, and 71 km in the third hour.

Please let me know if you need any further assistance!