Question

Два мальчик Егор и Никита живут в одном доме одновременно вышли из дома и направились в школу.Егор половину всего времени затраченного на дорогу шел со скоростью 5км/ч а затем шел со скоростью 4 км/ч .Никита же первую половину всего пути от дома до школы шел со скоростью 4 км/ч а вторую со скоростью 5 км/ч .Кто из школьников пришел в школу раньше?

Answer 1

Оба мальчика пришли одновременно, логически подумать: сначала Егор шел со скоростью 5км/ч, а Никита наоборот со скоростью 4км/ч, а затем наоборот Егор стал идти со скоростью 4км/ч, а Никита со скоростью 5км/ч.

Answer 2

Analysis:

To determine who arrived at school first, we need to compare the time taken by Egor and Nikita to travel from home to school. We are given the speeds at which they traveled during different parts of the journey.

Let's calculate the time taken by each of them and compare the results.

Calculation:

Let's assume the total distance from home to school is D.

Egor's journey: - Egor traveled the first half of the distance at a speed of 5 km/h. - He then traveled the second half of the distance at a speed of 4 km/h.

Nikita's journey: - Nikita traveled the first half of the distance at a speed of 4 km/h. - He then traveled the second half of the distance at a speed of 5 km/h.

To find the time taken by each of them, we can use the formula:

Time = Distance / Speed

Let's calculate the time taken by Egor and Nikita.

Egor's time: - Time taken for the first half of the distance: (0.5 * D) / 5 - Time taken for the second half of the distance: (0.5 * D) / 4

Nikita's time: - Time taken for the first half of the distance: (0.5 * D) / 4 - Time taken for the second half of the distance: (0.5 * D) / 5

Comparison:

To determine who arrived at school first, we need to compare the total time taken by Egor and Nikita.

If Egor's total time is less than Nikita's total time, then Egor arrived at school first. Otherwise, Nikita arrived at school first.

Let's compare the total times taken by Egor and Nikita.

Answer:

To determine who arrived at school first, we need to compare the total times taken by Egor and Nikita.

Let's calculate the total times taken by Egor and Nikita and compare the results.

Egor's total time: - Time taken for the first half of the distance: (0.5 * D) / 5 - Time taken for the second half of the distance: (0.5 * D) / 4 - Total time: (0.5 * D) / 5 + (0.5 * D) / 4

Nikita's total time: - Time taken for the first half of the distance: (0.5 * D) / 4 - Time taken for the second half of the distance: (0.5 * D) / 5 - Total time: (0.5 * D) / 4 + (0.5 * D) / 5

To determine who arrived at school first, we need to compare the total times taken by Egor and Nikita.

Let's simplify the expressions and compare the total times.

Simplifying Egor's total time: - Total time: (0.5 * D) / 5 + (0.5 * D) / 4 - Simplifying the expression: (2D + 2.5D) / 20 - Simplified total time: (4.5D) / 20

Simplifying Nikita's total time: - Total time: (0.5 * D) / 4 + (0.5 * D) / 5 - Simplifying the expression: (1.25D + D) / 20 - Simplified total time: (2.25D) / 20

Comparing the total times: - Egor's total time: (4.5D) / 20 - Nikita's total time: (2.25D) / 20

Since Egor's total time is greater than Nikita's total time, Nikita arrived at school first.

Please note that the above calculations assume constant speeds throughout the journey and do not take into account any other factors that may affect the travel time.