Question

Решить задачу из города А в город В выехала грузовая машина.спустя0,5 ч спустя 1,2 ч из пункта А вслед за ней выехал автобус.через 0,8 ч после своеговыезда он отстовал от машины на 24 км найдите скорость автобуса если известно что она больше скорости грузовой машины на 30 км/ч

Answer 1

Пусть скорость автобуса х,
тогда грузовика х-30  км/ч.
Грузовик проехал за  1,2+0,8=2 часа путь, равный 2*(х-30) км.
Автобус  ехал 0,8 часа и проехал 0,8х км.
Разница в расстоянии по условию равна 24 км.
Составим уравнение:
2(х-30) -0,8х = 24
2х-60-0,8х=24
1,2х = 84
х=84/1,2 = 840/12= 70 км/ч
Ответ: 70.

Answer 2

Problem Analysis

We are given that a truck traveled from city A to city B, and after 0.5 hours, a bus also started from city A to city B. After 1.2 hours, the bus was 24 km ahead of the truck. We need to find the speed of the bus, knowing that it is 30 km/h faster than the truck.

Solution

Let's assume the speed of the truck is x km/h. Since the bus is 30 km/h faster than the truck, the speed of the bus is (x + 30) km/h.

We can use the formula distance = speed × time to solve this problem.

The truck traveled for 0.5 hours before the bus started. Therefore, the distance traveled by the truck in 0.5 hours is 0.5x km.

After 1.2 hours, the bus was 24 km ahead of the truck. So, the distance traveled by the bus in 1.2 hours is (1.2(x + 30)) km.

According to the problem, the bus traveled 24 km more than the truck in 0.8 hours. Therefore, the distance traveled by the bus in 0.8 hours is (0.8(x + 30)) km.

We can set up the following equation based on the distances traveled by the truck and the bus:

0.5x + 0.8(x + 30) = 1.2(x + 30) + 24

Now, let's solve this equation to find the value of x.

Calculation

Expanding the equation:

0.5x + 0.8x + 24 = 1.2x + 36 + 24

Combining like terms:

1.3x + 24 = 1.2x + 60

Subtracting 1.2x from both sides:

0.1x + 24 = 60

Subtracting 24 from both sides:

0.1x = 36

Dividing both sides by 0.1:

x = 360

Therefore, the speed of the truck is 360 km/h.

Since the speed of the bus is 30 km/h faster than the truck, the speed of the bus is (360 + 30) km/h = 390 km/h.

Answer

The speed of the bus is 390 km/h.

Note: The answer is based on the information provided in the problem statement.