Question

Помогите решить задачу!!! От двух пристаней отошли одновременно навстречу друг другу катер и лодка. Они встретились через 4 часа. Скорость лодки 20км/ч, а скорость катера в 3 раза больше. Чему равно расстояние между пристанями?

Answer 1

Расстояние между ними - 320 км

Answer 2

1).20*3=60 км\ч скорость катера    2).20+60=80 км\ч скорость сближения
3)80*4=320 км расстояние между пристанями

Answer 3

Problem Analysis

We are given that a boat and a motorboat start from two different piers and meet after 4 hours. The speed of the boat is 20 km/h, and the speed of the motorboat is 3 times greater. We need to find the distance between the piers.

Solution

Let's assume the distance between the piers is d km.

The boat's speed is 20 km/h, so in 4 hours, it will cover a distance of 20 km/h * 4 h = 80 km.

The motorboat's speed is 3 times greater than the boat's speed, so its speed is 3 * 20 km/h = 60 km/h. In 4 hours, the motorboat will cover a distance of 60 km/h * 4 h = 240 km.

Since the boat and the motorboat meet after 4 hours, the sum of their distances traveled should be equal to the distance between the piers.

Therefore, we can set up the equation: 80 km + 240 km = d km.

Simplifying the equation, we find that the distance between the piers is d = 320 km.

Answer

The distance between the piers is 320 km.

Verification

Let's verify the answer using the given information.

The boat's speed is 20 km/h, so in 4 hours, it will cover a distance of 20 km/h * 4 h = 80 km.

The motorboat's speed is 3 times greater than the boat's speed, so its speed is 3 * 20 km/h = 60 km/h. In 4 hours, the motorboat will cover a distance of 60 km/h * 4 h = 240 km.

The sum of the distances covered by the boat and the motorboat is 80 km + 240 km = 320 km, which matches the calculated distance between the piers.

Therefore, the answer is verified.

Conclusion

The distance between the piers is 320 km.