Question

Из пунктов A и B одновременно навстречу друг другу выехал велосипедист и вышел пешеход. Через какое время они встретятся , если велосипедисту на весь путь требуется 40 мин, а пешеходу 2 часа?

Answer 1

Обозначим весь путь от А до Б через S
перейдем к единым единицам измерения, например к часам
тогда 40 мин = 2/3 ч
найдем скорость каждого
пешеход S/2
велосипедист $\frac{S}{ \frac{2}{3}}= \frac{3S}{2}$
найдем их общую скорость сближения
$\frac{S}{2}+ \frac{3S}{2}= \frac{4S}{2}= \frac{2S}{1}= \frac{S}{ \frac{1}{2}}$
Ответ: встретятся они через 1/2 часа

Answer 2

Problem Analysis

We are given that a cyclist and a pedestrian start simultaneously from points A and B towards each other. We need to determine the time it takes for them to meet if the cyclist takes 40 minutes to cover the entire distance and the pedestrian takes 2 hours.

Solution

To solve this problem, we can use the formula: time = distance / speed.

Let's assume the distance between points A and B is d.

The cyclist's speed can be calculated as d / 40 minutes.

The pedestrian's speed can be calculated as d / 2 hours.

Since they are moving towards each other, their combined speed is the sum of their individual speeds.

Let's calculate the time it takes for them to meet.

Calculation

The cyclist's speed is d / 40 minutes.

The pedestrian's speed is d / 2 hours.

Their combined speed is (d / 40 minutes) + (d / 2 hours).

To convert the pedestrian's speed to minutes, we need to multiply it by 60: d / (2 hours) * 60 = d / 120 minutes.

Therefore, their combined speed is (d / 40 minutes) + (d / 120 minutes) = (3d + d) / 120 minutes = 4d / 120 minutes = d / 30 minutes.

To find the time it takes for them to meet, we can use the formula time = distance / speed.

Substituting the values, we get time = d / (d / 30 minutes) = 30 minutes.

Therefore, the cyclist and the pedestrian will meet after 30 minutes.

Answer

The cyclist and the pedestrian will meet after 30 minutes.

Explanation

When the cyclist and the pedestrian start simultaneously from points A and B towards each other, they will meet after 30 minutes. This is because the cyclist takes 40 minutes to cover the entire distance, while the pedestrian takes 2 hours. By calculating their speeds and using the formula time = distance / speed, we find that their combined speed is d / 30 minutes, where d is the distance between points A and B. Therefore, they will meet after 30 minutes