Question

Задача.школа заказала в швейной мастерской спортивную форму в колличестве 60 штук. 1 швея может выполнить весь заказ за 20 дней,2-ой для выполнения задания требуется 3/5 этого времени, а третьей -в 2целых1/2 раза больше времени чем второй.за сколько выполнят заказ три швеи работая совместно

Answer 1

Всю работу примем за единицу.
1) 1: 20 = 1/20 часть заказа выполнит 1-ая швея за день
2) 20 * 3/5 = 12(дней) уйдёт на выполнение заказа у 2-ой швеи
3) 12 * 2,5 = 30(дней) уйдёт на выполнение заказа у 3-ей швеи
4) 1 : 12 = 1/12 часть заказа выполнит 2 швея за день
5) 1 : 30 = 1/30 часть заказа выполнит 3 швея за день
6) 1/20 + 1/12 + 1/30 =3/60 + 5/60 + 2/60 = 10/60 = 1/6 часть
     заказа выполнят три швеи за 1 день, работая вместе
7) 60 : 1/6 = (за) 10 дней
Ответ: за 10 дней три швеи выполнят заказ, работая вместе.

Answer 2

1) 20:5+3 7( дн.) для 2 швеи
2) 7+ 2 1/2 9 целых 1/2
3) 1*9+2 9/2
4) 7*2+9 28дн
5) 28+20+7 55 дн

Answer 3

Problem Analysis

The school has placed an order for 60 units of a sports uniform from a sewing workshop. There are three seamstresses involved in completing the order. The first seamstress can complete the entire order in 20 days. The second seamstress requires 3/5 of the time taken by the first seamstress to complete the task. The third seamstress requires 2 1/2 times the time taken by the second seamstress to complete the task. We need to determine how long it will take for the three seamstresses to complete the order if they work together.

Solution

Let's calculate the time required by each seamstress to complete the task.

1. The first seamstress can complete the entire order in 20 days. 2. The second seamstress requires 3/5 of the time taken by the first seamstress. Therefore, the second seamstress will require (3/5) * 20 = 12 days to complete the task. 3. The third seamstress requires 2 1/2 times the time taken by the second seamstress. Therefore, the third seamstress will require (2 1/2) * 12 = 30 days to complete the task.

Now, let's calculate the time required for the three seamstresses to complete the order if they work together.

To find the time required when working together, we can use the formula:

Total time = (1 / (1/time1 + 1/time2 + 1/time3))

Substituting the values:

Total time = (1 / (1/20 + 1/12 + 1/30))

Let's calculate the total time required.

Calculation

Total time = (1 / (1/20 + 1/12 + 1/30))

Total time = (1 / (0.05 + 0.0833 + 0.0333))

Total time = (1 / 0.1666)

Total time ≈ 6 days

Answer

Therefore, if the three seamstresses work together, they will be able to complete the order in approximately 6 days.

Please note that the above calculation assumes that the three seamstresses work at a constant rate and there are no other factors that may affect the completion time.