Question

Расстояние между городами равно 280 км. Из этих городов начали одновременно двигаться навтсречу друг другу два автомобиля - первый со скоростью 90 км/ч, а второй со скоростью 72 км/ч. Задача определить время, прошедшее до встречи автомобилей.

Answer 1

X70+x90=280
160x=280
  x=1.75=1h45min

Answer 2

Problem Analysis

We are given that two cars start moving towards each other from two cities that are 280 km apart. The first car has a speed of 90 km/h, and the second car has a speed of 72 km/h. We need to determine the time it takes for the cars to meet.

Solution

To solve this problem, we can use the formula: time = distance / speed. Since the cars are moving towards each other, their combined speed is the sum of their individual speeds.

Let's calculate the time it takes for the cars to meet.

Calculation

The distance between the cities is 280 km. The speed of the first car is 90 km/h. The speed of the second car is 72 km/h.

The combined speed of the cars is 90 km/h + 72 km/h = 162 km/h.

Using the formula time = distance / speed, we can calculate the time it takes for the cars to meet:

time = 280 km / 162 km/h.

Calculating this, we find:

time ≈ 1.728 hours.

Therefore, it takes approximately 1.728 hours for the cars to meet.

Answer

The time it takes for the two cars to meet is approximately 1.728 hours.

Note: The answer has been calculated based on the given information and the formula for time, distance, and speed.