Question

Первая бригада может выполнить работу за 8 часов, а вторая в 1 7/8 раза медленнее. За сколько часов могут выполнить работу обе бригады, работая вместе?

Answer 1

Ответ:

Пошаговое объяснение:

вторая бригада за 8×1 7/8=8×15/8=

=15часов .Пусть весь обьем работ

=1 находим сумму производительности труда

1/8 +1/15 =23/120

если будут работать вместе то,

1÷23/120= 120/23 =5 5/23часа

Answer 2

Calculating the Combined Work Time of Two Crews

To calculate the combined work time of both crews, we can use the concept of "work done equals rate multiplied by time."

Let's denote: - T1 as the time taken by the first crew to complete the work - T2 as the time taken by the second crew to complete the work - R2 as the rate of the second crew (which is 1 7/8 times slower than the first crew)

We know that the first crew can complete the work in 8 hours, and the second crew is 1 7/8 times slower.

Using the formula: Total work = Work done by the first crew + Work done by the second crew

We can express the work done by the second crew in terms of the work done by the first crew: Work done by the second crew = (1/1 7/8) * Work done by the first crew

Now, we can calculate the combined work time of both crews.

Step 1: Calculate the work rate of the second crew. Step 2: Use the work rates to find the combined work time of both crews.

Step 1: Calculate the Work Rate of the Second Crew

The work rate of the second crew can be calculated using the given information that it is 1 7/8 times slower than the first crew.

The work rate of the second crew = 1 / (1 7/8) * (work rate of the first crew)

Step 2: Calculate the Combined Work Time of Both Crews

The combined work time can be calculated using the work rates of both crews.

Combined work time = Total work / (Work rate of the first crew + Work rate of the second crew)

Let's calculate the combined work time using the given information.

Solution

The work rate of the second crew = 1 / (1 7/8) * (1 job / 8 hours) = 8 / 15 job per hour.

Now, we can calculate the combined work time: Combined work time = 1 job / (1 job / 8 hours + 8 / 15 job per hour) = 1 job / (23 / 15 job per hour) = 15 / 23 hours.

Therefore, the combined work time of both crews, working together, is 15/23 hours.