Question

Старший брат идёт от дома до школы 30 мин.младший брат 40 мин..Младший брат вышел из дома на 5 мин.раньше старшего.Через сколько минут старший брат догонит младшего?

Answer 1

Через 5 минут старший брат догонит младшего брата.

Answer 2

Problem Analysis

We are given that the older brother takes 30 minutes to go from home to school, while the younger brother takes 40 minutes. The younger brother leaves home 5 minutes earlier than the older brother. We need to determine how many minutes it will take for the older brother to catch up to the younger brother.

Solution

To solve this problem, we can set up an equation based on the given information. Let's assume that the time it takes for the older brother to catch up to the younger brother is represented by the variable x.

We know that the younger brother has a head start of 5 minutes, so when the older brother starts, the younger brother has already been walking for 5 minutes. Therefore, the younger brother has covered a distance of 40 * 5 = 200 meters.

In the time it takes for the older brother to catch up, he will cover a distance of 30 * x meters.

Since both brothers are walking at a constant speed, we can set up the equation:

200 + 30x = 40x

Simplifying the equation:

200 = 10x

Dividing both sides by 10:

x = 20

Therefore, it will take the older brother 20 minutes to catch up to the younger brother.

Answer

The older brother will catch up to the younger brother in 20 minutes.

Explanation

The younger brother leaves home 5 minutes earlier than the older brother. In this time, the younger brother has already covered a distance of 200 meters. The older brother walks at a speed of 30 meters per minute, so it will take him 20 minutes to cover the same distance and catch up to the younger brother