Question

От пристани отплатить лодка и одновременно навстречу ей от пункта А отплатить плот. лодка и плот встретились через 2 часа. Через 30 мин. После встречи лодка прибыла в пункт А.Через какое время после встречи плот прибыл на пристань

Answer 1

2+0,5=2,5 часа лодка была в пути.
2,5÷0,5=5 раз скорость лодки больше скорости плота.
2×5= 10 часов плот был в пути.
10-2=8 ч. Через 8 часов после встречи с лодкой плот прибыл на пристань.
Ответ: через 8 часов.

Answer 2

Problem Analysis

To solve this problem, we need to calculate the time it takes for the boat and the raft to meet, and then determine the time it takes for the raft to reach the dock after meeting the boat.

Boat and Raft Meeting Time Calculation

Let's denote the speed of the boat as b and the speed of the raft as r. The time it takes for the boat and the raft to meet can be calculated using the formula: \[ \frac{d}{b + r} = 2 \]

Where: - \( d \) is the distance between the dock and point A.

Boat Arrival Time Calculation

After the meeting, the boat travels for an additional 30 minutes to reach point A. We need to calculate the time it takes for the boat to reach point A after the meeting.

Raft Arrival Time Calculation

We also need to calculate the time it takes for the raft to reach the dock after the meeting.

Solution

Let's calculate the time it takes for the boat and the raft to meet, and then determine the time it takes for the raft to reach the dock after meeting the boat.

Boat and Raft Meeting Time Calculation

Using the formula: \[ \frac{d}{b + r} = 2 \] We can solve for \( d \) using the given information.

Boat Arrival Time Calculation

After the meeting, the boat travels for an additional 30 minutes to reach point A. We can calculate the time it takes for the boat to reach point A after the meeting.

Raft Arrival Time Calculation

We also need to calculate the time it takes for the raft to reach the dock after the meeting.

Let's proceed with the calculations.