Question

Два насоса могут осушить котлован за 2 ч. За сколько часов мог бы осушить котлован второй насос, работая один, если первому насосу на это понадобилось бы 3ч?

Answer 1

два насоса, работая вместе, за час осушают 1/2 котлована. Первый насос, работая самостоятельно, за час осушает 1/3 котлована. Следовательно, второй насос, работая самостоятельно, за час осушает 1/2 - 1/3 = 1/6, то есть он осушает котлован за 6 часов 

Answer 2

x - время для 2-го насоса: 

1/3 + 1/x = 1/2

1/x = 1/2 - 1/3

1/x = 1/6

x = за 6 часов.

Ответ: за 6 часов

Answer 3

Calculating Pump Efficiency

To calculate the time it would take for the second pump to drain the excavation pit working alone, we can use the concept of pump efficiency. If the first pump can drain the pit in 3 hours and the second pump can do it in 2 hours when working together, we can find the efficiency of each pump.

The efficiency of a pump is given by the formula:

Efficiency = Work / Time

Where "Work" is the amount of work done and "Time" is the time taken to do that work.

Calculating Efficiency of Each Pump

Let's assume that the total work to drain the pit is 1 unit.

- The first pump's efficiency is therefore 1/3, as it can drain the pit in 3 hours. - The second pump's efficiency is 1/2, as it can drain the pit in 2 hours.

Calculating the Time for the Second Pump Alone

Now, if the second pump were to work alone, we can use its efficiency to calculate the time it would take for it to drain the pit.

The formula for time taken is:

Time = Work / Efficiency

Substituting the values: Time = 1 / (1/2) = 2 hours

So, the second pump would take 2 hours to drain the pit if it were working alone.

This calculation assumes that the efficiency of the pumps remains constant, which may not always be the case in practical scenarios.