Question

Из А в В по реке плот проплывает за 40 часов, а катер за 4 часа. За какое время катер вернется в А?

Answer 1

1/40- скорость плота= скорости течения, 1/4 скорость катера
1- весь путь
1:(1/4-1/40)=40/9=4 целых 4/9 часа
Ответ:4 целых 4/9 часа

Answer 2

Возьмем скорость течения за а, тогда 9а - это скорость катиера собственная, значит против течения его скорость - 8а
возьмем расстояние из А в В за 1. Тогда 1/а=40, тогда 1/8а=40/8=5
Ответ: 5 часов.
Рад, если все понятно.

Answer 3

Calculating the Time for the Boat to Return

To calculate the time for the boat to return from B to A, we can use the formula: time = distance / speed.

Given that the raft takes 40 hours and the motorboat takes 4 hours to travel from A to B, we can calculate the speed of each vessel using the formula above.

The speed of the raft is: speed of raft = distance / time taken by raft.

The speed of the motorboat is: speed of motorboat = distance / time taken by motorboat.

Let's calculate the speeds of the raft and the motorboat using the given information.

The speed of the raft is: speed of raft = distance / 40.

The speed of the motorboat is: speed of motorboat = distance / 4.

Now, we can calculate the time it takes for the motorboat to return from B to A using the speed of the motorboat.

The time for the motorboat to return from B to A is: time = distance / speed of motorboat.

Let's calculate the time for the motorboat to return from B to A.