Question

Три машины выезжают с элеватора в 8ч утра в разных направлениях.На элеватор первая машина возвращаяется через каждые 3ч,вторая- через 4ч,третья - через 6ч.В котором часу машины встретятся на элеваторе,если их движение выполняется по графику?

Answer 1

В 20 часов встретятся все на элеваторе
первая машина выполнит 4 рейса 3*4=12 часов
вторая 3 рейса 3*4=12 часов
третья  2 рейса 2*6=12 часов.

Answer 2

Problem Analysis

We have three cars leaving an elevator in different directions at 8:00 AM. The first car returns to the elevator every 3 hours, the second car returns every 4 hours, and the third car returns every 6 hours. We need to determine at what time the cars will meet at the elevator.

Solution

To find the time when the cars will meet at the elevator, we need to find the least common multiple (LCM) of the return times for each car. The LCM will give us the time at which all three cars will simultaneously return to the elevator.

The return times for the three cars are 3 hours, 4 hours, and 6 hours. To find the LCM, we can list the multiples of each return time until we find a common multiple.

The multiples of 3 are: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, ...

The multiples of 4 are: 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, ...

The multiples of 6 are: 6, 12, 18, 24, 30, 36, 42, 48, 54, 60, ...

From the lists above, we can see that the least common multiple of 3, 4, and 6 is 12. Therefore, the cars will meet at the elevator 12 hours after they initially left.

Since the cars left at 8:00 AM, they will meet at the elevator at 8:00 PM.

Therefore, the cars will meet at the elevator at 8:00 PM if their movement is according to the given schedule.