Question

Із міста А в місто В виїхав вантажний автомобіль, рухаючись зі швидкістю 47км/год. Коли він проїхав s км, то слідом за ним виїхав легковий автомобіль, швидкість якого 75км/год. До міста В обидва автомобілі приїхали одночасно. Знайти s, якщо відомо, що вантажний автомобіль був у дорозі на 3 години довше, ніж легковий.

Answer 1

Ответ:

пусть масса раствора первоначально х.

в первом растворе 0,07х вещества, во втором 0,17х.

масса нового раствора 2х. масса вещества в новом растворе 0,24х. находим отношение массы вещества к массе раствора и * на 100. 0,24х/2х*100 = 12. это и есть ответ

Объяснение:

Answer 2

Problem Analysis

We are given that a truck travels from city A to city B at a speed of 47 km/h, and after traveling a certain distance, a car starts from city A to city B at a speed of 75 km/h. Both vehicles reach city B at the same time. We need to find the distance traveled by the truck before the car starts.

Solution

Let's assume that the distance traveled by the truck before the car starts is s km.

We know that the truck traveled for 3 hours longer than the car. Since the speed of the truck is 47 km/h, the total time traveled by the truck is (3 + t) hours, where t is the time traveled by the car.

We can set up the following equation to represent the relationship between distance, speed, and time for both vehicles:

Distance traveled by the truck = Distance traveled by the car

Using the formula Distance = Speed × Time, we can write:

47 × (3 + t) = 75 × t

Simplifying the equation:

141 + 47t = 75t

141 = 75t - 47t

141 = 28t

Solving for t:

t = 141 / 28

t = 5

Now that we have the value of t, we can substitute it back into the equation to find the distance traveled by the truck:

Distance traveled by the truck = 47 × (3 + t)

Distance traveled by the truck = 47 × (3 + 5)

Distance traveled by the truck = 47 × 8

Distance traveled by the truck = 376 km

Therefore, the truck traveled a distance of 376 km before the car started.

Answer

The truck traveled a distance of 376 km before the car started its journey.