Question

На Аэродром должен был прилететь самолет с ценным грузом. Для транспортировки его из Города на Аэродром была отправлена машина. Самолет приземлился раньше установленного срока, и привезенный груз был отправлен в Город на машине спецслужб. Через 40 минут езды машина спецслужб встретила на дороге машину из Города, которая приняла груз и, не задерживаясь, повернула обратно. В Город она прибыла на 30 минут раньше, чем было запланировано. На сколько минут раньше установленного срока приземлился самолет?

Answer 1

40+40= 80
80-30=50минут

Answer 2

Calculation of the Early Landing Time of the Plane

To determine the number of minutes the plane landed before the scheduled time, we need to analyze the given information.

1. The valuable cargo was supposed to be transported from the City to the Airport by car. 2. However, the plane landed earlier than the scheduled time, and the cargo was sent back to the City by a special service car. 3. After a 40-minute drive, the special service car met a car from the City, which took the cargo and immediately turned back. 4. The car from the City arrived in the City 30 minutes earlier than planned.

To calculate the early landing time of the plane, we need to consider the time it took for the special service car to reach the City and return to the Airport.

Let's assume that the total time taken by the special service car to reach the City and return to the Airport is represented by variable X.

The car from the City took 40 minutes to reach the special service car on the road. After handing over the cargo, it immediately turned back and arrived in the City 30 minutes earlier than planned. Therefore, the total time taken by the car from the City is X + 40 - 30 = X + 10 minutes.

Since the special service car and the car from the City met on the road, the total time taken by the special service car is also X + 10 minutes.

Now, let's consider the time it took for the special service car to reach the City and return to the Airport separately.

The special service car took X minutes to reach the City and X minutes to return to the Airport. Therefore, the total time taken by the special service car is 2X minutes.

Since we know that the total time taken by the special service car is both X + 10 minutes and 2X minutes, we can equate these two expressions and solve for X.

2X = X + 10

Simplifying the equation, we find:

X = 10

Therefore, the special service car took 10 minutes to reach the City and 10 minutes to return to the Airport.

Now, let's calculate the early landing time of the plane.

The car from the City arrived in the City 30 minutes earlier than planned, which means it saved 30 minutes of travel time. Since the special service car took 10 minutes to reach the City, the remaining time saved is 30 - 10 = 20 minutes.

Therefore, the plane landed 20 minutes before the scheduled time.