Question

Первый экскаватор может выкопать траншею за 8 часов,а второй-за 4 часа.Какую часть траншеи останется выкопать после 2 часов совместной работы двух экскаваторов? Помогите пожалуйста!

Answer 1

3/4 части останется прокопать

Answer 2

Походу 2 но я незнаю

Answer 3

Problem Analysis

We have two excavators, where the first excavator can dig a trench in 8 hours and the second excavator can dig the same trench in 4 hours. We need to determine the portion of the trench that remains to be dug after 2 hours of working together.

Solution

To solve this problem, we can calculate the rate at which each excavator digs the trench and then determine the portion of the trench that remains after 2 hours.

Let's assume that the total length of the trench is 1 unit.

The first excavator can dig the entire trench in 8 hours, so its digging rate is 1 trench per 8 hours. This means that in 1 hour, the first excavator can dig 1/8 of the trench.

Similarly, the second excavator can dig the entire trench in 4 hours, so its digging rate is 1 trench per 4 hours. This means that in 1 hour, the second excavator can dig 1/4 of the trench.

Now, let's calculate the portion of the trench that remains after 2 hours of working together.

In 2 hours, the first excavator can dig 2/8 = 1/4 of the trench, and the second excavator can dig 2/4 = 1/2 of the trench.

Therefore, the total portion of the trench that remains after 2 hours of working together is:

1 - (1/4 + 1/2) = 1 - (2/8 + 4/8) = 1 - 6/8 = 1 - 3/4 = 1/4

So, after 2 hours of working together, 1/4 of the trench remains to be dug.

Answer

After 2 hours of working together, 1/4 of the trench remains to be dug.