Question

Первая бригада может выполнить задание за 30 дней, а вторая за 50 дней. Успеют ли они при совместной работе выполнить задание за 19 дней?

Answer 1

1)30-100%
19-х% 
19*100/30=63% - первая бригада за 19 дней
2) 50-100%
19-х%
19*100/50=38% - вторая бригада за 19 дней
3) 63%+38%=101% - значит успеют

Answer 2

2015-04-16T15:51:04+00:00
1 : 30 = 1/30 - производительность первой бригады;
1 : 50 =1/50 - производительность второй бригады.
1/30 + 1/50 = 8/150 = 1/18,75 - совместная производительность.
1 : 1/18,75 = 18,75 (д) - будет выполнена работа совместно.
18,75 < 19
Ответ: да.

Answer 3

Calculation of Work Rates

To determine if the first and second brigades can complete the task in 19 days when working together, we need to calculate their individual work rates.

Let's assume that the work rate of the first brigade is represented by x (in units of work per day) and the work rate of the second brigade is represented by y (in units of work per day).

According to the given information, the first brigade can complete the task in 30 days, which means their work rate is 1/30 of the task per day. Similarly, the second brigade can complete the task in 50 days, so their work rate is 1/50 of the task per day.

Work Rate Equation

When the two brigades work together, their work rates are additive. Therefore, the equation representing their combined work rate is:

x + y = 1/30 + 1/50.

Solving the Equation

To determine if they can complete the task in 19 days, we need to find the combined work rate of the two brigades when they work together.

Let's solve the equation:

x + y = 1/30 + 1/50

To simplify the equation, we can find a common denominator for the fractions:

x + y = (5/150) + (3/150)

Combining the fractions:

x + y = 8/150

Simplifying further:

x + y = 4/75

Now, we know that the combined work rate of the two brigades is 4/75 of the task per day.

Determining if the Task Can Be Completed in 19 Days

To determine if the task can be completed in 19 days, we need to check if the combined work rate of the two brigades is sufficient.

Let's calculate the work done in 19 days by multiplying the combined work rate by the number of days:

Work done in 19 days = (4/75) * 19

Calculating the result:

Work done in 19 days = 76/75

Since the work done in 19 days is greater than the total amount of work required (which is 1), we can conclude that the first and second brigades will be able to complete the task in 19 days when working together.

Therefore, they will be able to complete the task in 19 days.

Please note that the calculations provided are based on the given information and assumptions made.