Question

От двух пристаней, находящихся на расстоянии 510км друг от друга, отплыли одновременно на встречу друг другу катер и моторная лодка. Они встретились через 17ч. Катер шёл со средней скоростью 19км/ч. С какой скоростью шла лодка?

Answer 1

1)Чтобы найти сколько расстояний проплыл катер:

19 * 17 = 323(км)

2) Чтобы найти сколько расстояний проплыла лодка:

510 - 323 = 187(км)

3) Чтобы найти скорость лодки:

187 : 17 = 11(км/ч)

Ответ: лодка шла со скоростью 11км/ч

 

Обратная задача:

Скорость лодки - 11км/ч - проплыла ?км

Катер - проплыл 323 км - ? км/ч

Встретились через - 17 ч 

Сколько км между пристанями?

1) Чтобы найти сколько км проплылы лодка:

11 * 17 = 187(км)

2) Чтобы найти расстояние между пристанями:

187 + 323 = 510(км)

Ответ: между двумя пристанями 510км 

Answer 2

Problem Analysis

We are given that a boat and a motorboat set sail from two different ports that are 510 km apart. They sail towards each other and meet after 17 hours. The boat has an average speed of 19 km/h. We need to determine the speed of the motorboat.

Solution

Let's assume the speed of the motorboat is x km/h.

The boat and the motorboat are traveling towards each other, so their combined speed is the sum of their individual speeds.

The boat's speed is given as 19 km/h, and the motorboat's speed is x km/h. Therefore, the combined speed is 19 km/h + x km/h.

We know that the distance between the two ports is 510 km, and they meet after 17 hours. The formula to calculate the distance is:

Distance = Speed × Time

For the boat, the distance traveled is 19 km/h × 17 h = 323 km.

For the motorboat, the distance traveled is x km/h × 17 h.

Since they meet in the middle, the sum of their distances traveled should be equal to the total distance between the ports:

323 km + (x km/h × 17 h) = 510 km

Now we can solve this equation to find the value of x.

Calculation

Let's solve the equation:

323 km + (x km/h × 17 h) = 510 km

Rearranging the equation:

x km/h × 17 h = 510 km - 323 km

x km/h × 17 h = 187 km

Dividing both sides by 17 h:

x km/h = 187 km / 17 h

x km/h ≈ 11 km/h

Answer

The motorboat was traveling at a speed of approximately 11 km/h.

Explanation

The boat and motorboat meet after 17 hours of sailing. The boat's speed is given as 19 km/h, and the distance traveled by the boat is 323 km. By subtracting the distance traveled by the boat from the total distance between the ports (510 km), we can find the distance traveled by the motorboat. Dividing this distance by the time (17 hours), we find that the motorboat was traveling at a speed of approximately 11 km/h.