Question

Моторная лодка прошла путь 12 км по течению и обратно за 2,5 ч. А в другой раз за 1 ч 20 мин. прошла по течению реки 4 км, а против течения 8 км. Найди собственную скорость лодки и скорость течения реки.

Answer 1

Всё подробно написала в решении:Vсоб=10; Vтеч=2-это ответ.

Answer 2

Problem Analysis

We are given the following information: - The motorboat traveled a distance of 12 km downstream and back in 2.5 hours. - In another instance, it traveled 4 km downstream and 8 km upstream in 1 hour and 20 minutes.

We need to find the speed of the motorboat and the speed of the river current.

Solution

Let's assume the speed of the motorboat is x km/h and the speed of the river current is y km/h.

1. First, let's calculate the time taken to travel 12 km downstream and back in 2.5 hours. - The time taken to travel downstream is 12 / (x + y) hours. - The time taken to travel upstream is 12 / (x - y) hours. - The total time taken is 2.5 hours.

Using the above information, we can form the equation: (12 / (x + y)) + (12 / (x - y)) = 2.5 2. Next, let's calculate the time taken to travel 4 km downstream and 8 km upstream in 1 hour and 20 minutes. - The time taken to travel downstream is 4 / (x + y) hours. - The time taken to travel upstream is