Question

моторная лодка прошла путь от А до В по течению реки за 3 часа, а обратный путь за 4 часа. Найдите скорость течения реки, если известно, что скорость лодки в стоячей воле 20 км/ч​

Answer 1

1) 20:3=6,66
2) 6,66×4=26,66

Answer 2

Calculating the River's Current Speed

To calculate the speed of the river's current, we can use the formula: speed of the boat in still water = (speed of the boat downstream + speed of the boat upstream) / 2 and speed of the current = (speed of the boat downstream - speed of the boat upstream) / 2

Given: - Time taken downstream = 3 hours - Time taken upstream = 4 hours - Speed of the boat in still water = 20 km/h

Using the above formula, we can calculate the speed of the river's current.

The speed of the boat downstream can be calculated as: speed of the boat downstream = distance / time = AB / 3

The speed of the boat upstream can be calculated as: speed of the boat upstream = distance / time = AB / 4

Substituting the values, we get: speed of the boat downstream = AB / 3 speed of the boat upstream = AB / 4

Now, we can calculate the speed of the river's current using the formula: speed of the current = (speed of the boat downstream - speed of the boat upstream) / 2

Let's calculate the speed of the river's current: speed of the current = (AB / 3 - AB / 4) / 2

Solving the above equation, we get the speed of the river's current.

Calculation

The speed of the river's current can be calculated using the given formula: speed of the current = (AB / 3 - AB / 4) / 2

Substituting the values, we get: speed of the current = (AB / 3 - AB / 4) / 2

Now, solving the equation: speed of the current = (AB / 3 - AB / 4) / 2

Result

The speed of the river's current is AB / 12.

Therefore, the speed of the river's current is AB / 12.