Question

Из двух пунктов,расстояние между которыми 40 км,навстречу друг другу одновременно отправились пешеход и велосепедист.Скорость велосепедиста в 4 раза больше скорости пешехода.Найдите скорость пешехода и велосепедиста если известно что они встретились через 2.5 часа после своего выхода.?! Помогите пожалуйста решить!!!

Answer 1

Problem Analysis

We are given that a pedestrian and a cyclist start simultaneously from two points that are 40 km apart. The cyclist's speed is 4 times greater than the pedestrian's speed. We need to find the speeds of the pedestrian and the cyclist if they meet after 2.5 hours.

Solution

Let's assume the speed of the pedestrian is x km/h. Since the cyclist's speed is 4 times greater, the cyclist's speed is 4x km/h.

We can use the formula speed = distance / time to find the distances covered by the pedestrian and the cyclist.

The distance covered by the pedestrian is x * 2.5 km, and the distance covered by the cyclist is 4x * 2.5 km.

Since they meet, the sum of the distances covered by the pedestrian and the cyclist should be equal to the total distance between them, which is 40 km.

So we have the equation: x * 2.5 + 4x * 2.5 = 40.

Simplifying the equation, we get: 2.5x + 10x = 40.

Combining like terms, we have: 12.5x = 40.

Dividing both sides by 12.5, we get: x = 40 / 12.5.

Calculating the value of x, we find that the speed of the pedestrian is approximately 3.2 km/h.

Since the cyclist's speed is 4 times greater, the speed of the cyclist is approximately 4 * 3.2 = 12.8 km/h.

Therefore, the speed of the pedestrian is approximately 3.2 km/h and the speed of the cyclist is approximately 12.8 km/h.

Answer

The speed of the pedestrian is approximately 3.2 km/h and the speed of the cyclist is approximately 12.8 km/h.