Question

Моторная лодка против течения реки проплыла 10 км,а по течению 9 км, при этом по течению она шла 45 мин, а против течения 1ч 15 минут. Найдите собственную скорость лодки и скорость течения реки

Answer 1

45 мин = 3/4 часа 
1 час 15 мин = 1 1/4 ( часа ) = 5/4 часа 
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X ( км/час ) собственная скорость ; y ( км/час ) скорость течения 
Система уравнений 
10 / ( x - y ) = 5/4 
9 / ( x + y ) = 3/4 
Решение 
40 = 5( x - y ) 
36 = 3( x + y ) 
x - y = 8 
x + y = 12 
x = ( 12 + 8 ) : 2 
x = 10 ( км/час ) собственная скорость 
y = 10 - 8 = 2 ( км/час ) скорость течения 

Answer 2

Calculation of Boat's Speed and River's Current Speed

To find the boat's speed and the river's current speed, we can use the following formula:

Boat's Speed = (Distance traveled downstream) / (Time taken downstream)

River's Current Speed = (Distance traveled upstream) / (Time taken upstream)

Given information: - Distance traveled downstream = 9 km - Time taken downstream = 45 minutes = 0.75 hours - Distance traveled upstream = 10 km - Time taken upstream = 1 hour 15 minutes = 1.25 hours

Let's calculate the boat's speed and the river's current speed.

Boat's Speed = (9 km) / (0.75 hours) = 12 km/h.

River's Current Speed = (10 km) / (1.25 hours) = 8 km/h.

Therefore, the boat's speed is 12 km/h, and the river's current speed is 8 km/h.