Question

За 4 ч езды на автомате и 7 ч езды на поезде туристы проехали 640 км. Какова скорость поезда, если она на 5 км/ч больше скорости автомашины?

Answer 1

Х скорость поезда
х-5 скорость автомашины
4(х-5)+7х=640
4х-20+7х=640
11х=660
х=60км/час скорость поезда

Answer 2

Calculation of Train Speed

To calculate the speed of the train, we need to determine the speed of the car first. We are given that the tourists traveled 640 km in 4 hours by car and 7 hours by train. The speed of the train is 5 km/h faster than the speed of the car.

Let's assume the speed of the car is x km/h. Therefore, the speed of the train would be (x + 5) km/h.

The distance traveled by the car can be calculated using the formula: distance = speed × time.

For the car: distance = speed × time 640 km = x km/h × 4 hours

Solving this equation, we can find the speed of the car.

For the train: distance = speed × time 640 km = (x + 5) km/h × 7 hours

Solving this equation, we can find the speed of the train.

Let's calculate the speeds of the car and the train.

Calculation:

Using the given information, we can set up the following equations:

Equation 1: 640 km = x km/h × 4 hours Equation 2: 640 km = (x + 5) km/h × 7 hours

Solving Equation 1 for x: x km/h = 640 km / 4 hours x km/h = 160 km/h

Substituting the value of x into Equation 2: 640 km = (160 km/h + 5 km/h) × 7 hours 640 km = 165 km/h × 7 hours

Simplifying the equation: 640 km = 1155 km/h × hours

Dividing both sides by 7 hours: 640 km / 7 hours = 165 km/h

Answer:

The speed of the train is 165 km/h.

Please note that the above calculation assumes constant speeds for both the car and the train throughout the entire journey.