Question

Решите задачу!! по действиям. Расстояние между двумя пристанями по течению реки катер проходит 8 часов, а плот за 72 часа. Сколько времени потратит катер на тот же путь по озеру?

Answer 1

72:8=9(ч)
Ответ:9часов

Answer 2

Problem Analysis

To solve this problem, we need to find the time it takes for a boat to travel the same distance on a lake without the assistance of the current. We are given the time it takes for a boat to travel the distance with the current for both a motorboat and a raft.

Solution

Let's denote the speed of the motorboat as x and the speed of the current as y. The speed of the raft is 1/9 of the speed of the motorboat.

The formula for the speed of the boat with the current is (x + y) and the formula for the speed of the boat against the current is (x - y).

We can use the formula: speed = distance / time to solve for the speed of the motorboat and the speed of the current.

Calculations

Given that the motorboat takes 8 hours and the raft takes 72 hours to travel the same distance with the current, we can set up the following equations:

1. For the motorboat: (x + y) = distance / 8 2. For the raft: (1/9)(x + y) = distance / 72

We can solve these equations to find the values of x and y.

Solution

After solving the equations, we find that the speed of the motorboat is 9x and the speed of the current is 8x.

To find the time it takes for the motorboat to travel the same distance on the lake, we can use the formula: time = distance / speed.

Final Answer

Using the speed of the motorboat and the distance, we can calculate the time it takes for the motorboat to travel the same distance on the lake.