Question

Теплоход прошел по течению реки 220 км, а затем 100 км по озеру. сколько времени он находился в пути, если его собственная скорость 20 км в ч, а скорость течения реки 2 км в ч?

Answer 1

1.  20 + 2 = 22 км/час ( скорость теплохода по течению)
2.  220 : 22 = 10 час (плыл теплоход по реке)
3.  100 : 20 = 5 час (плыл теплоход по озеру)
4.  10 + 5 = 15 час 
ОТВЕТ:  15 час находился теплоход в пути

Answer 2

Calculation of Time Taken

To calculate the time taken by the boat, we need to consider the distance traveled on the river and the distance traveled on the lake, as well as the boat's own speed and the speed of the river current.

Given: - Distance traveled on the river: 220 km - Distance traveled on the lake: 100 km - Boat's own speed: 20 km/h - Speed of the river current: 2 km/h

To calculate the time taken on the river, we divide the distance by the effective speed of the boat, which is the boat's own speed minus the speed of the river current. Similarly, we calculate the time taken on the lake using the boat's own speed.

Let's calculate the time taken on the river first:

Distance on the river = 220 km Effective speed on the river = Boat's own speed - Speed of the river current = 20 km/h - 2 km/h = 18 km/h

Time taken on the river = Distance on the river / Effective speed on the river

Now, let's calculate the time taken on the lake:

Distance on the lake = 100 km Speed on the lake = Boat's own speed = 20 km/h

Time taken on the lake = Distance on the lake / Speed on the lake

Finally, we add the time taken on the river and the time taken on the lake to get the total time taken by the boat.

Calculation Steps:

1. Calculate the time taken on the river: - Distance on the river = 220 km - Effective speed on the river = 18 km/h (Boat's own speed - Speed of the river current) - Time taken on the river = Distance on the river / Effective speed on the river

2. Calculate the time taken on the lake: - Distance on the lake = 100 km - Speed on the lake = 20 km/h (Boat's own speed) - Time taken on the lake = Distance on the lake / Speed on the lake

3. Calculate the total time taken: - Total time taken = Time taken on the river + Time taken on the lake

Let's perform the calculations:

1. Calculate the time taken on the river: - Distance on the river = 220 km - Effective speed on the river = 18 km/h - Time taken on the river = 220 km / 18 km/h = 12.22 hours

2. Calculate the time taken on the lake: - Distance on the lake = 100 km - Speed on the lake = 20 km/h - Time taken on the lake = 100 km / 20 km/h = 5 hours

3. Calculate the total time taken: - Total time taken = Time taken on the river + Time taken on the lake = 12.22 hours + 5 hours = 17.22 hours

Therefore, the boat was in transit for approximately 17.22 hours.