Question

Расстояние между пристанями на реке 189 км. Сколько времени понадобится теплоходу чтобы проплыть туда и обратно если его скорость по течению равна 27км/ч а против течения 21км/ч?

Answer 1

1) 189:27=7 (ч.) - потребуется на движение по течению реки

2) 189:21=9 (ч.) - потребуется на движение против течения реки

3) 7+9=16 (ч.)

Ответ: чтобы проплыть туда и обратно, теплоходу потребуется 16 часов.

 

Answer 2

Calculation of Time Required for the Round Trip

To calculate the time required for the round trip, we need to consider the speed of the boat both with and against the current.

Given: - Distance between the piers: 189 km - Speed of the boat with the current: 27 km/h - Speed of the boat against the current: 21 km/h

To calculate the time required for the boat to travel from one pier to another, we can use the formula:

Time = Distance / Speed

Let's calculate the time required for the boat to travel from one pier to another and back:

1. Time required to travel downstream (with the current): - Distance: 189 km - Speed: 27 km/h - Time = 189 km / 27 km/h = 7 hours

2. Time required to travel upstream (against the current): - Distance: 189 km - Speed: 21 km/h - Time = 189 km / 21 km/h = 9 hours

To calculate the total time required for the round trip, we add the time required for the downstream and upstream journeys:

Total time = Time downstream + Time upstream = 7 hours + 9 hours = 16 hours

Therefore, it will take the boat approximately 16 hours to complete the round trip.