Question

Из двух пунктов реки, расстояние между которыми равно 19 км, навстречу друг другу движутся две моторные лодки. Лодка, идущая по течению, собственная скорость которой равна 9 км/ч, до встречи прошла 1 ч, другая лодка, собственная скорость которой равна 8 км/ч, до встречи шла 1,5 ч. Найдите скорость течения реки.

Answer 1

Решение на фото))))))))))))))))))))))

Answer 2

Problem Analysis

We are given two motorboats moving towards each other on a river. The distance between them is 19 km. One boat is moving downstream with a speed of 9 km/h and reaches the meeting point in 1 hour. The other boat is moving upstream with a speed of 8 km/h and reaches the meeting point in 1.5 hours. We need to find the speed of the river's current.

Solution

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

The speed of the boat moving downstream is the sum of its own speed and the speed of the current, which is 9 + x km/h. It takes this boat 1 hour to cover the distance of 19 km, so we can write the equation:

distance = speed × time

19 = (9 + x) × 1

Simplifying the equation, we get:

19 = 9 + x

x = 19 - 9

x = 10 km/h

Therefore, the speed of the river's current is 10 km/h.

Answer

The speed of the river's current is 10 km/h.