Question

1 автовокзала вышли одновременно в противоположных направлениях два автобуса остановились когда расстояние между ними стало 900 километров скорость первого автобуса была 70 километров час что на 10 километров час меньше скорости второго автобуса Сколько времени автобусы были в пути?

Answer 1

Ответ 6 часов
70+80=150
900:150=6

Answer 2

1) 70+10= 80 ( км/ч) - скорость второго автобуса
2)80+ 70 = 150 ( км/ч) - общая скорость
3)900:150= 6 (ч) общее время

Answer 3

Problem Analysis

We are given that two buses leave a bus station simultaneously in opposite directions. The buses stop when the distance between them becomes 900 kilometers. The speed of the first bus is 70 kilometers per hour, which is 10 kilometers per hour slower than the speed of the second bus. We need to determine how much time the buses were in motion.

Solution

To solve this problem, we can use the formula: time = distance / speed.

Let's denote the speed of the second bus as x kilometers per hour. The distance covered by the first bus can be calculated as 70t, where t is the time in hours. The distance covered by the second bus can be calculated as xt.

According to the problem, the sum of the distances covered by both buses is equal to 900 kilometers. Therefore, we can write the equation:

70t + xt = 900

We also know that the speed of the first bus is 10 kilometers per hour slower than the speed of the second bus. Therefore, we can write another equation:

x = 70 + 10

Now we have a system of two equations that we can solve to find the values of t and x.

Solution Steps

1. Substitute the value of x from the second equation into the first equation. 2. Solve the resulting equation for t. 3. Substitute the value of t into the second equation to find x. 4. Calculate the time the buses were in motion using the value of t.

Let's solve the problem step by step.

Solution Steps

1. Substitute the value of x from the second equation into the first equation:

70t + (70 + 10)t = 900

2. Simplify the equation:

80t = 900

3. Solve for t:

t = 900 / 80 = 11.25

4. Substitute the value of t into the second equation to find x:

x = 70 + 10 = 80

5. Calculate the time the buses were in motion using the value of t:

time = t = 11.25 hours

Therefore, the buses were in motion for 11.25 hours.

Answer

The buses were in motion for 11.25 hours.