Question

Баба-Яга пролетела 45 мин с двумя остановками через равные промежутки времени. За второй промежуток она пролетела на 10 км больше, чем за первый, а за третий на 20 км больше, чем за второй промежуток. Найдите ее скорость на втором промежутке времени, если всего она пролетела 70 км.

Answer 1

70-45-10=15(км)-ее скорость

Answer 2

Problem Analysis

We are given that Baba Yaga flew for 45 minutes with two stops, and the distances she flew during each interval of time are in arithmetic progression. We need to find her speed during the second interval of time, given that she flew a total distance of 70 km.

Solution

Let's assume that Baba Yaga's speed during the first interval of time is v km/h. According to the problem, her speed during the second interval is 10 km/h more than during the first interval, and her speed during the third interval is 20 km/h more than during the second interval.

To find her speed during the second interval, we can set up the following equations:

- Distance covered during the first interval: v * t km, where t is the duration of the first interval. - Distance covered during the second interval: (v + 10) * t km. - Distance covered during the third interval: (v + 30) * t km.

We are given that the total distance covered is 70 km, so we can write the equation:

v * t + (v + 10) * t + (v + 30) * t = 70

Simplifying the equation, we get:

3v * t + 40t = 70

Since we know that the total duration of the flight is 45 minutes, we can convert it to hours by dividing by 60:

t = 45/60 = 0.75 hours

Substituting the value of t into the equation, we get:

3v * 0.75 + 40 * 0.75 = 70

Simplifying further:

2.25v + 30 = 70

2.25v = 40

v = 40 / 2.25

v ≈ 17.78 km/h

Therefore, Baba