Question

Катер плыл 3 часа. В первый час он проплыл половину всего пути, во второй час - половину оставшегося пути, а последние 40 км он преодолел в третий час. Какой путь проплыл катер за 3 ч?

Answer 1

40+40=80 половина всего пути
80×2=160 весь путь
Ответ:160 км

Answer 2

Problem Analysis

We are given that a boat sailed for 3 hours. In the first hour, it covered half of the total distance. In the second hour, it covered half of the remaining distance. And in the third hour, it covered the last 40 km. We need to find the total distance covered by the boat in these 3 hours.

Solution

Let's assume the total distance covered by the boat is D km.

According to the given information: - In the first hour, the boat covered half of the total distance, which is D/2 km. - In the second hour, the boat covered half of the remaining distance, which is (D - D/2)/2 = D/4 km. - In the third hour, the boat covered the remaining 40 km.

To find the total distance D, we can add up the distances covered in each hour:

D/2 + D/4 + 40 = D

Simplifying the equation: - Multiply the entire equation by 4 to eliminate the denominators: 2D + D + 160 = 4D - Combine like terms: 3D + 160 = 4D - Subtract 3D from both sides: 160 = D

Therefore, the total distance covered by the boat in 3 hours is 160 km.

Answer

The boat covered a total distance of 160 km in 3 hours.