Question

Как решить задачу?человек за 25 минут прошел 1,2 км, затем отдыхал 30 минут,а затем побежал еще 800 метров за 5 минут. какова была его средняя скорость на всем пути? какова былабы его средняя скорость, если бы он не отдыхал?

Answer 1

(1200+800)/(25+5)= ответ

Answer 2

Problem Analysis

To solve this problem, we need to calculate the average speed of a person who walks 1.2 km in 25 minutes, rests for 30 minutes, and then runs an additional 800 meters in 5 minutes. We also need to calculate the average speed if the person did not take a rest.

Solution

To find the average speed, we can use the formula:

Average Speed = Total Distance / Total Time

Let's calculate the average speed step by step.

1. Calculate the total distance covered: - The person walks 1.2 km. - Then the person runs an additional 800 meters. - So the total distance covered is 1.2 km + 0.8 km = 2 km.

2. Calculate the total time taken: - The person walks for 25 minutes. - Then the person rests for 30 minutes. - Finally, the person runs for 5 minutes. - So the total time taken is 25 minutes + 30 minutes + 5 minutes = 60 minutes.

3. Convert the total time to hours: - 60 minutes is equal to 1 hour.

4. Calculate the average speed: - Average Speed = Total Distance / Total Time - Average Speed = 2 km / 1 hour - Average Speed = 2 km/h

Therefore, the person's average speed for the entire journey, including the rest, is 2 km/h.

Now, let's calculate the average speed if the person did not take a rest.

1. Calculate the total distance covered: - The person walks 1.2 km. - Then the person runs an additional 800 meters. - So the total distance covered is 1.2 km + 0.8 km = 2 km.

2. Calculate the total time taken: - The person walks for 25 minutes. - Then the person runs for 5 minutes. - So the total time taken is 25 minutes + 5 minutes = 30 minutes.

3. Convert the total time to hours: - 30 minutes is equal to 0.5 hours.

4. Calculate the average speed: - Average Speed = Total Distance / Total Time - Average Speed = 2 km / 0.5 hours - Average Speed = 4 km/h

Therefore, if the person did not take a rest, the average speed would be 4 km/h.

Conclusion

In conclusion, the person's average speed for the entire journey, including the rest, is 2 km/h. If the person did not take a rest, the average speed would be 4 km/h.