Question

Первая бригада может выполнить работу за 4 1/3 часа, а вторая на 3/4 часа медленее . За сколько часов могут выполнить работу обе бригады , работая вместе

Answer 1

Первая б . 13/3часа
вторая б . 13/3+3/4=61/12часа
пер. б . 1час 1:13/3 часть
вторая б 1час выполн . 1:61/12 часть
вместе 1час выполн .3/13+12/61 часть
3/13+12/61=339/793
вместе пусть выполнить работу. х часа
х*339/793=1
х=793/339=2 целых115/339. (час)

Answer 2

Problem Analysis

We are given that the first brigade can complete a job in 4 1/3 hours, and the second brigade is 3/4 hour slower. We need to determine how long it will take for both brigades to complete the job when working together.

Solution

To find the time it takes for both brigades to complete the job when working together, we can add the individual times it takes for each brigade to complete the job and then divide by the combined rate of work.

Let's calculate the time it takes for each brigade to complete the job:

- The first brigade can complete the job in 4 1/3 hours. - The second brigade is 3/4 hour slower, so it takes (4 1/3 + 3/4) hours for the second brigade to complete the job.

Now, let's find the combined rate of work for both brigades:

- The combined rate of work is the sum of the individual rates of work. The rate of work is the reciprocal of the time it takes to complete the job.

Let's calculate the combined rate of work:

- The rate of work for the first brigade is 1 job per (4 1/3) hours. - The rate of work for the second brigade is 1 job per (4 1/3 + 3/4) hours.

Now, let's find the time it takes for both brigades to complete the job when working together:

- The time it takes for both brigades to complete the job is the reciprocal of the combined rate of work.

Let's calculate the time it takes for both brigades to complete the job when working together:

- The combined rate of work is (1/(4 1/3) + 1/(4 1/3 + 3/4)) jobs per hour. - The time it takes for both brigades to complete the job when working together is the reciprocal of the combined rate of work.

The time it takes for both brigades to complete the job when working together is approximately 2.4 hours.

Calculation

Let's calculate the time it takes for both brigades to complete the job when working together:

- The time it takes for both brigades to complete the job when working together is approximately 2.4 hours.

Answer

The first brigade can complete the job in 4 1/3 hours, and the second brigade is 3/4 hour slower. When both brigades work together, it takes approximately 2.4 hours to complete the job.