Question

Два поезда идут на встречу друг другу, скорость первого — 80 км, а скорость второго — в 1 1/7 раза меньше. Через какое воемя они встретятся если расстояние между ними равно 70 км?

Answer 1

Они встретятся через  32 минуты 20 секунд.

Answer 2

Problem Analysis

We are given two trains traveling towards each other. The speed of the first train is 80 km/h, and the speed of the second train is 1/7 times slower than the first train. The distance between them is 70 km. We need to determine the time it takes for the trains to meet.

Calculation

To find the time it takes for the trains to meet, we can use the formula: time = distance / relative speed.

Let's calculate the relative speed of the two trains. The second train's speed is 1/7 times slower than the first train's speed. Therefore, the relative speed can be calculated as follows:

Relative speed = Speed of first train + Speed of second train

Speed of second train = Speed of first train * (1 - 1/7)

Now, we can substitute the values into the formula to find the time it takes for the trains to meet:

Time = Distance / Relative speed

Calculation Steps

1. Speed of second train = 80 km/h * (1 - 1/7) = 80 km/h * (6/7) = 480/7 km/h 2. Relative speed = 80 km/h + 480/7 km/h = (560 + 480)/7 km/h = 1040/7 km/h 3. Time = 70 km / (1040/7 km/h) = 70 km * (7/1040) h = 0.475 hours

Answer

The two trains will meet in approximately 0.475 hours.