Question

Моторная лодка шла 40 минут по течению реки и 1 час против течения реки и прошла за это время 37 км. Найдите скорость лодки в стоячей воде , если скорость течения реки равна 1,5км/ч.

Answer 1

составляем уравнение
(х+1,5)*2\3+(х-1,5)*1=37
2\3*х+1+х-1,5=37
6/3*х=37,5
х=18,75км\ч

Р.S.возможны погрешности в решении,ну не правильно поделила или умножила 

Answer 2

Calculating the Boat's Speed in Still Water

To calculate the speed of the boat in still water, we can use the formula: Speed of boat in still water = (Speed downstream + Speed upstream) / 2

Given: - Time taken downstream = 40 minutes = 40/60 hours = 2/3 hours - Time taken upstream = 1 hour - Distance covered in both directions = 37 km - Speed of the river's current = 1.5 km/h

First, let's calculate the speed of the boat downstream and upstream.

Speed downstream: - Let's assume the speed of the boat in still water as x km/h. - The speed downstream is the sum of the boat's speed in still water and the speed of the river's current: (x + 1.5) km/h.

Speed upstream: - The speed upstream is the difference between the boat's speed in still water and the speed of the river's current: (x - 1.5) km/h.

Now, we can use the given time and distance to find the boat's speed in still water.

Calculations

We can use the formula: Speed = Distance / Time

Downstream: - Speed downstream = Distance / Time = 37 km / (2/3) hours = 37 km / (2/3) hours = 37 km / (2/3) hours = 55.5 km/h

Upstream: - Speed upstream = Distance / Time = 37 km / 1 hour = 37 km/h

Now, we can solve for the boat's speed in still water using the formula: Speed of boat in still water = (Speed downstream + Speed upstream) / 2

Substitute the values: - (x + 1.5 + x - 1.5) / 2 = 55.5 - (2x) / 2 = 55.5 - x = 55.5

The speed of the boat in still water is 27.75 km/h.