Question

Экскурсанты за день прошли 12,5 км. С утра они шли 3 час(-а), а после обеда — ещё 2 час(-а). Сколько километров экскурсанты прошли утром, если после обеда их скорость снизилась на 2 км/ч. С какой скоростью шли экскурсанты утром? Буду рад решению!Желательно до утра)

Answer 1

Ответ:

9,9 км

Объяснение:

Answer 2

Ответ:

9,9

Объяснение:

Это задача формы: скорость(V), время(T), расстояние(S).

Пусть v = неизвестное скорость.

S = 12,5 км. v - неизвестное скорость  . T = 5 ч.

Предлагаю делать такую табличку:

Утро: t = 3, V = v

После обеда: t = 2, V = (v - 2)

Общее расстояние: 12,5 км.

Получается следующая формула: 3×v  + 2×(v-2) = 12,5

3v + 2v - 4 = 12,5

5v = 16,5

V = 3,3 - скорость, с которой шли экскурсанты утром.

Утром они шли 3 часа, соответственно, 3,3 × 3 = 9,9 км.

Answer 3

Problem Analysis

The problem states that a group of tourists walked a total of 12.5 km in one day. They walked for 3 hours in the morning and an additional 2 hours after lunch. The question asks for the distance the tourists walked in the morning and the speed at which they walked.

Solution

To find the distance the tourists walked in the morning, we need to subtract the distance they walked after lunch from the total distance of 12.5 km.

Let's denote the distance walked in the morning as x km. The distance walked after lunch can be calculated by subtracting x from 12.5 km: 12.5 km - x km.

We also know that the speed after lunch was 2 km/h slower than the speed in the morning. Let's denote the speed in the morning as v km/h. The speed after lunch can be calculated by subtracting 2 km/h from v: v km/h - 2 km/h.

We can use the formula distance = speed × time to find the distance walked in the morning. The time walked in the morning is given as 3 hours. Therefore, we have the equation: x km = v km/h × 3 h.

Now we have two equations: 1. x km = v km/h × 3 h 2. 12.5 km - x km = (v km/h - 2 km/h) × 2 h

We can solve this system of equations to find the values of x and v.

Solution Steps

1. Let's solve the first equation for x in terms of v: x = 3v. 2. Substitute this value of x into the second equation: 12.5 - 3v = 2(v - 2). 3. Simplify the equation: 12.5 - 3v = 2v - 4. 4. Combine like terms: 12.5 + 4 = 2v + 3v. 5. Simplify further: 16.5 = 5v. 6. Solve for v: v = 16.5 / 5. 7. Calculate the value of v: v = 3.3 km/h. 8. Substitute the value of v into the first equation to find x: x = 3 × 3.3. 9. Calculate the value of x: x = 9.9 km.

Answer

The tourists walked a distance of 9.9 km in the morning, and their speed in the morning was 3.3 km/h.

Please note that the above solution assumes a linear relationship between speed and time, which may not always be accurate in real-life scenarios.