Question

9.55. Первая бригада может выполнить заказ за 30 дней. Другой бригаде для выполнения этого заказа потребуется вре-смени на 20 % меньше, чем первой. Третья бригада может выпол-нить этот заказ в полтора раза быстрее первой. За сколько днейбудет выполнен весь заказ при совместной работе всех трех бри-гад?​

Answer 1

Ответ:

Вся работа 1

1/а- такую часть работы выполняет первая бригада за 1 час;

1/b - такую часть работы выполняет вторая бригада за 1 час;

(1/a+1/b) - такую часть работы выполняют за 1 час обе бригады, работая вместе;

всю работу они выполнят за х часов:

(1/a+1/b)х=1

x(a+b)=ab

x= ab/(a+b)

Ответ: две бригады, работая вместе, выполнят работу за столько часов: ab/(a+b)

Пошаговое объяснение:

Answer 2

#### Problem Analysis We have three brigades working on a project, and each brigade has a different time requirement to complete the project compared to the first brigade. We need to determine how long it will take for all three brigades to complete the project when working together. #### Given Information - First brigade: 30 days to complete the project. - Second brigade: 20% less time than the first brigade. - Third brigade: 1.5 times faster than the first brigade. #### Solution To find the total time required for all three brigades to complete the project, we need to calculate the time required by each brigade and then add them together. Let's calculate the time required by each brigade: - Second brigade: 20% less time than the first brigade. This means the second brigade will take 80% of the time taken by the first brigade. - Time required by the second brigade = 80% of 30 days = **24 days**. - Third brigade: 1.5 times faster than the first brigade. This means the third brigade will take 2/3 of the time taken by the first brigade. - Time required by the third brigade = 2/3 of 30 days = **20 days**. Now, let's calculate the total time required for all three brigades to complete the project by adding the times calculated above: - Total time required = time required by the first brigade + time required by the second brigade + time required by the third brigade - Total time required = 30 days + 24 days + 20 days = **74 days**. Therefore, it will take all three brigades working together a total of 74 days to complete the project. #### Answer When all three brigades work together, the entire order will be completed in **74 days**. Note: The sources provided did not contain specific information related to this problem. Therefore, the solution was derived based on the given information and mathematical calculations.