Question

Экскурсанты за день прошли 16,6 км. С утра они шли 4 час(-а), а после обеда еще 2 час(-а). Сколько километров экскурсанты прошли утром, если после обеда их скорость снизилась на 1 км/ч. С какой скоростью шли экскурсанты утром?

Answer 1

Пусть х км/ч – скорость до обеда
(х–1) км/ч – скорость после обеда
До обеда:
t = 4 ч
v = х км/ч
тогда S до = 4х км
После обеда:
t = 2 ч
v = (х–1) км/ч
тогда S после = 2(х–1) км
Весь путь: S = S до + S после
4х + 2(х–1) = 16,6
4х + 2х – 2 = 16,6
6х = 18,6
х = 18,6 : 6
х = 3,1 (км/ч) – скорость до обеда

S до = 4 * 3,1 = 12,4 км – путь до обеда

Answer 2

Problem Analysis

The excursionists walked a total of 16.6 km in one day. They walked for 4 hours in the morning and 2 hours after lunch. The speed of the excursionists decreased by 1 km/h after lunch. We need to determine how many kilometers the excursionists walked in the morning and at what speed they were walking.

Solution

Let's assume that the excursionists walked x kilometers in the morning. After lunch, their speed decreased by 1 km/h, so they walked x - 1 kilometers in the afternoon.

We know that the total distance walked in one day is 16.6 km. Therefore, we can write the equation:

x + (x - 1) = 16.6

Simplifying the equation:

2x - 1 = 16.6

Adding 1 to both sides:

2x = 17.6

Dividing both sides by 2:

x = 8.8

Therefore, the excursionists walked 8.8 km in the morning.

To find the speed at which the excursionists walked in the morning, we need to divide the distance walked by the time taken. Since they walked for 4 hours in the morning, the speed is:

Speed = Distance / Time = 8.8 km / 4 hours = 2.2 km/h

Therefore, the excursionists walked 8.8 km in the morning at a speed of 2.2 km/h.

Answer

The excursionists walked 8.8 km in the morning, and their speed was 2.2 km/h.