Question

За 3 часа велосипедист проехал 35 км. За первые два часа он преодолел расстояние 24 2/25 км. , аза вторые два часа -23 1/5 км. Сколько километров проезжал велосипедист за каждый час ?

Answer 1

Три неизвестных - X, Y, Z пишем три уравнения.
1) X +  Y + Z = 35 км - за три часа
2) Х + Y = 24 2/25 км -  за первые два часа
3) Y + Z = 23 1/5 км - за вторые два часа
Сложим ур. 2) + 3)
4) X + 2*Y + Z = 24 2/25 + 23 1/5 =  47 7/25 
Вычитаем из ур. 4) ур. 1) и находим неизвестное -  Y.
5) Y = 47 7/25 - 35 = 12 7/25 км -  за второй час.
Подставим в ур. 2) и 3) и найдем неизвестные - X и Z.
6) X = 24 2/25 - Y = 11 4/5 км -  за первый час
7) Z = 23 1/5 - Y = 11 2/5 км - за третий час.

Answer 2

Calculating the Bicyclist's Speed

To calculate the bicyclist's speed for each hour, we can use the information provided about the distance covered in the first two hours and the next two hours.

The total distance covered by the bicyclist in 3 hours is 35 km.

Distance Covered in the First Two Hours

The bicyclist covered a distance of 24 2/25 km in the first two hours.

Distance Covered in the Next Two Hours

The bicyclist covered a distance of 23 1/5 km in the next two hours.

To find the speed for each hour, we can use the formula: \[ \text{Speed} = \frac{\text{Distance}}{\text{Time}} \]

Calculating the Speed for Each Hour

1. Speed for the First Hour: - Distance covered in the first hour = 24 2/25 km - Time taken = 1 hour - Speed = \( \frac{24 \frac{2}{25}}{1} \) km/h

2. Speed for the Second Hour: - Distance covered in the second hour = 24 2/25 km (total distance for 2 hours) - 24 2/25 km (distance covered in the first hour) - Time taken = 1 hour - Speed = \( \frac{24 \frac{2}{25} - 24 \frac{2}{25}}{1} \) km/h

3. Speed for the Third Hour: - Distance covered in the third hour = 35 km (total distance for 3 hours) - 24 2/25 km (distance covered in the first two hours) - Time taken = 1 hour - Speed = \( \frac{35 - 24 \frac{2}{25}}{1} \) km/h

Conclusion

By calculating the distances covered in each hour, we can determine the speed for each hour.