Question

Первая бригада может выполнить работы по ремонту водопровода за 5 дней, а вторая в одну целую 1/4 раза быстрей .Смогут ли они отремонтировать водопровод за 3 дня если будут работать вместе.

Answer 1

все работы-1

5:1 1/4=5:5/4=5*4/5=4 дня понадобится второй бригаде, чтобы выполнить все работы

1:5=1/5 всех работ в день производительность первой бригады

1:4=1/4 всех работ в день производительность второй бригады

1/5+1/4=4/20+5/20=9/20 всех работ в день производительность двух бригад вместе

1:9/20=20/20:9/20=20/20*20/9=400/180=2 2/9 дней понадобится двум бригадам, чтобы закончить всю работу, значит они отремонтируют водопровод раньше, чем за 3 дня

Answer 2

Analysis and Solution

To determine if the first and second brigades can repair the water pipeline in 3 days when working together, we need to calculate their combined efficiency and compare it to the required time.

According to the information provided, the first brigade can complete the repair work in 5 days, while the second brigade is 1/4 times faster than the first brigade. Let's calculate the time it takes for the second brigade to complete the work:

Time taken by the second brigade = (1/4) * (time taken by the first brigade)

Now, let's substitute the value of the time taken by the first brigade:

Time taken by the second brigade = (1/4) * 5 = 1.25 days

Therefore, the second brigade can complete the repair work in 1.25 days.

To determine if they can complete the work in 3 days when working together, we need to calculate their combined efficiency:

Combined efficiency = 1 / (1/time taken by the first brigade + 1/time taken by the second brigade)

Substituting the values:

Combined efficiency = 1 / (1/5 + 1/1.25) = 1 / (0.2 + 0.8) = 1 / 1 = 1

The combined efficiency is 1, which means that the first and second brigades can complete the work in the same time as the first brigade alone.

Therefore, if the first and second brigades work together, they will not be able to repair the water pipeline in 3 days. They will require the same amount of time as the first brigade alone, which is 5 days.

Please note that the calculations are based on the information provided and may not consider other factors that could affect the repair time.

Let me know if there is anything else I can help you with!